terça-feira, 24 de março de 2015

CLAUDIO COSTA: PHILOSOPHICAL TEXTS


DEAR READER!
THE AIM OF THIS 'BLOG' IS TO MAKE MY WORK IN PHILOSOPHY MORE ACCESSIBLE.
THERE ARE APPROXIMATELY 90 TEXTS, MOST OF THEM IN DRAFT FORM.
PAPERS WITH SOME INTEREST FOR THE PHILOSOPHICAL RESEARCH ARE MARKED WITH ONE OR MORE #.
COMMENTS AND OBJECTIONS WILL BE WELCOME!

PREZADO LEITOR! O OBJETIVO DESSE 'BLOG' É TORNAR MEUS TRABALHOS EM FILOSOFIA MAIS FACILMENTE ACESSÍVEIS. HÁ CERCA DE 90 TEXTOS, EM GERAL EM FORMA DE ESBOÇO. INTRODUÇÕES SÃO INDICADAS. TRABALHOS DE INTERESSE PARA EM TERMOS DE PESQUISA SÃO MARCADOS COM UM OU MAIS '#'. COMENTÁRIOS E OBJEÇÕES SERÃO BEM VINDOS!




ABOUT ME:

I am a CNPq researcher and full professor of philosophy at the UFRN (Brazil).
E-mail for contact: ruvstof@gmail.com

I made my M.S. in philosophy at the IFCS (Rio de Janeiro, 1982, with Raul Landin). Ph.D. at the University of Konstanz (1990 with Friedrich Kambartel and Gottfried Gabriel). Sabbatical stages of one year as a visiting scholar in the Hochschule für Philosophie, Muenchen (1995) (with Friedo Ricken), University of California at Berkeley (1999) (with John Searle), University of Oxford (2004) (with Richard Swinburne) and University of Konstanz (2009-10) (with Wolfgang Spohn).

AREAS OF INTEREST: All the central problems of philosophy.

MAIN PUBLISHED WORK: The Philosophical Inquiry (UPA: Langham 2002), "Free Will and the Soft Constraints of Reason" (Ratio 2006), "The Sceptical Deal with our Concept of External Reality" (Abstracta 2009), "A Perspectival Definition of Knowledge" (Ratio 2010), and "A Metadescriptivist Theory of Proper Names" (Ratio 2011); a corrected version of the ideas of the last paper are here presented under the title "Outline of a Theory of Proper Names". The best selection of papers in portuguese is Paisagens Conceituais (Rio de Janeiro: Tempo Brasileiro 2012). A selection of papers published in English containing improved versions of the papers cited above is the book Lines of Thought: Rethinking Philosophical Assumptions (Newcastle upon Tyne: Cambridge Scholars Publishing, 2014).


CURRENT RESEARCH: I am presently working in a book to be called Philosophical Semantics I: Building upon Wittgenstein and Frege. One of my aims is an attempt to reestablish the credibility of the internalist and cognitivist-descriptivist tradition concerning theories of reference. I believe that this can be done if we reconstruct the old theories in more sophisticated ways, able to solve the important challenges presented by Kripke, Donnellan, Putnam, Kaplan and others.





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segunda-feira, 23 de fevereiro de 2015

O QUE É SUBSTÂNCIA?







Texto didático para o curso de metafísica – C. F. Costa – ppgfil/UFRN



 O QUE É A SUBSTÂNCIA?
                                     
                                                           A natureza ama ocultar-se.
                                                           Heráclito                                         


     O termo substância é uma tradução da palavra latina substantia, que significa aquilo que está sob, que fundamenta. Substantia, por sua vez, é uma tradução latina do termo grego ousia, que significa ‘o ser’. Substância é um termo de arte filosófico que, diferentemente de muitos outros (como verdade, significado, causa...) não tem equivalente apropriado na linguagem ordinária. Nessa última chamamos geralmente de substância o stoff constitutivo das coisas como o ferro, o carbono, o plástico, o óleo de linhaça... o qual é quimicamente definível em termos de combinações de átomos com propriedades específicas. A palavra ‘coisa’ tem um significado aproximado. Ela se refere geralmente a objetos materiais. Mas a substância não é o mesmo que o objeto material, que tem todas as suas propriedades à mostra. Ela é aquilo que fundamenta, que em algum sentido está sob (sub-stare) a coisa visível.
     Qual é a razão original para a introdução do conceito de substância? A resposta é: para a explicação da mudança. Quando as coisas materiais mudam, mudam as suas propriedades. Um pedaço de cera, quando aquecido, deixa de ser sólido e opaco para tornar-se líquido e transparente. Nesse caso, por que dizemos que ele ainda é o mesmo? A resposta é: porque a sua substância permaneceu a mesma. Há dificuldades com essa resposta. Afinal, coisas como a massa e o peso do pedaço de cera também são propriedades, que no caso permaneceram as mesmas. No que se segue quero historiar brevemente a evolução do conceito de substância na filosofia, propondo no final que ele seja explicado em termos de conceitos físicos fundamentais.

     O conceito aristotélico de substância
     Aristóteles sugeriu vários conceitos de substância. Eles são supostamente complementares, mas ele não explicou suficientemente as relações entre eles. Podemos classificar os principais dentre esses conceitos como sendo 1) aquilo que não é predicável; 2) aquilo que existe independentemente; 3) aquilo que permanece através da mudança; 4) a união da matéria e da forma essencial.
     A definição de substância como aquilo que não é predicável é a seguinte:

Aquilo que é chamado de substância mais estritamente, primariamente e acima de tudo, é aquilo que nem é dito de um sujeito nem em um sujeito, por exemplo, o homem individual ou o cavalo individual(1).

     Aristóteles propõe aqui critérios lingüísticos: a substância é aquilo que não pode ser designado por um predicado como pertencendo a um sujeito ou estando nele, dando como exemplos de substâncias particulares concretos como este homem e aquele cavalo. Apesar de interessante, essa sugestão é ontologicamente insatisfatória, pois não chega a dizer o que a substância é.
     Na segunda definição, a substância é concebida por Aristóteles como aquilo que existe independentemente. Enquanto uma propriedade depende da substância para existir, a substância não depende da propriedade para existir. Se as substâncias primárias não existissem seria impossível para qualquer das outras coisas existir(2). Isso vale mesmo para o que ele chama de substâncias segundas, que são predicados distinguindo os tipos de coisa que são substâncias, como ‘...é um homem’, ‘...é um cavalo’. Sendo assim resta a pergunta: o que é aquilo que existe independentemente?
     Vejamos agora a concepção de substância como aquilo que permanece através da mudança:

O distintivo da substância é que ela é numericamente uma e a mesma e que é capaz de receber contrários. Em nenhum outro caso podemos ter algo numericamente único, que seja capaz de receber contrários.(3)

     Além da dificuldade colocada no início, essa definição trás consigo uma outra, levantada pelo próprio Aristóteles, qual seja: a de que há outras coisas que não são substâncias e que podem sofrer mudanças. Uma crença, por exemplo, pode deixar de ser considerada verdadeira para ser considerada falsa. A resposta de Aristóteles é que a mudança da crença é extrínseca a ela, enquanto a mudança na substância ocorre nela mesma; em outras palavras, só substâncias sofrem mudanças intrínsecas. Mas que dizer de uma superfície que muda a sua forma? Não é essa uma mudança intrínseca? Contudo, ninguém diria que a superfície é substancial.
     A quarta e mais sofisticada definição é a que aparece na Metafísica. Nesse texto, após rejeitar a idéia de que a substância seja apenas a matéria (o substrato), posto que isso não daria conta da separabilidade e individualidade da substância, ele conclui que

A forma e o composto de matéria e forma parecem ser mais substância do que a matéria(4).

      A substância é, pois, a forma individuadora da matéria(5). Contudo, à parte a dificuldade de que formas são universais, enquanto a substância é um particular, o que seria essa forma substancial? Os melhores candidatos seriam espécies como ‘homem’ e ‘cavalo’, dificilmente distinguíveis do que Aristóteles chamava de substâncias segundas (designata de nomes substantivais), que são categorias predicáveis da substância primeira, da substância em sentido próprio. Além disso, espécies são constituídas de propriedades, as quais são também universais. A última sugestão de Aristóteles é tão mais refinada quanto controversa.

O conceito de substância na filosofia moderna
     Filósofos como Descartes e Locke desenvolveram a idéia de que a substância é um substrato independente, em relação ao qual as propriedades ou atributos subsistem ou inerem. Descartes, como dualista, sugeriu a existência de duas substâncias: a extensa, constitutiva dos corpos físicos, e a pensante, constitutiva das almas e mais propriamente de Deus. Elas se distinguem pelos seus atributos essenciais, que são respectivamente a extensão e o pensamento(6). Por não se confundir com os seus atributos a substância torna-se assim um substrato nu.
     Também para Locke a substância tem a ver com um substrato nu que dá unidade aos atributos a ele inerentes. Como observou Locke:

Não podendo imaginar como as idéias subsistem por si mesmas, acostumamo-nos a supor um substrato no qual elas subsistem e do qual resultam, o qual chamamos de substância(7).

     Essa concepção de substância admite duas formas: 1) ela é o substrato nu, incognoscível; 2) ela é o complexo formado pelo substrato nu e pelo conjunto de qualidades a ele inerente que constituem a sua espécie (sortal), como o homem ou o cavalo.
     Em qualquer dessas versões ela é problemática. O teorista do substrato nu precisa atribuir ao substrato várias propriedades: ele deve ser tal que as propriedades devem subsistir nele, ele tem a propriedade de ser concreto, tem a propriedade de ser uma substância e, além disso, a propriedade de não ter nenhuma propriedade, o que parece tornar a idéia de substância contraditória. Além disso, a idéia de um substrato em si mesmo incognoscível não satisfaz um razoável princípio da verificação. E se isso vale para a primeira versão da teoria, vale também para a segunda.
     Outra teoria da substância é aquela segundo a qual ela se caracteriza por ser independente de outras entidades. Já vimos essa idéia em Aristóteles quando ele sugeriu que substâncias não são objetos de predicação. Contudo, ela aparece mais claramente em Descartes, segundo o qual substâncias são o que existe por si mesmo sem precisar de nenhuma outra coisa para existir. Para Descartes, a única coisa que satisfaz essa definição completamente é Deus; as outras substâncias são as que só dependem de Deus e de mais nada para existir.
     O filósofo que mais se valeu da teoria da independência da substância foi Spinoza. Eis a sua famosa definição:

Por substância entendo aquilo que é em si mesmo e que por si mesmo é concebido; ou seja: o seu conceito não requer o conceito de outra coisa de cujo conceito ele seja formado(8).

Nesse sentido, a substância não pode ter a sua existência causalmente produzida ou sustentada por qualquer entidade. Tal substância é para Spinoza o universo inteiro, o qual possui um número infinito de atributos, apenas dois deles sendo acessíveis à mente humana: a extensão e a consciência. Contudo, essa concepção se opõe ao senso comum, para o qual há muitas substâncias constitutivas das coisas particulares.
     A última concepção a ser considerada é a teoria do feixe (bundle ou cluster theory). Há duas versões fundamentais, ambas aludidas por Hume(9). A primeira é eliminativista: substâncias não existem. O que existe são feixes de entidades não-substanciais. A outra versão é reducionista: substâncias nada mais são do que os próprios feixes de entidades insubstanciais. Hume dá a entender essa última versão ao considerar que a idéia da substância é apenas a de uma coleção de idéias simples, unidas pela imaginação.
     Segundo essa última teoria, uma substância é um conjunto ou coleção de não-substâncias do tipo apropriado; uma maçã, por exemplo, constitui-se de certa cor, certo gosto, certo odor, figura e consistência que se encontram juntas. A noção de conjunto é aqui problemática, posto que conjuntos são entidades abstratas e substâncias são concretas. A palavra coleção é mais adequada, entendendo-se por ela uma soma mereológica (das partes) de entidades.
     Há também a questão da natureza dos componentes não-substanciais que compõem a coleção. Para uns trata-se de propriedades universais, como o vermelho em si e a forma esférica em si. A objeção a isso é que se a substância se identifica com um feixe de entidades abstratas, ela mesma passa a ser uma entidade abstrata. Ora, como a substância é intuitivamente uma entidade concreta, espácio-temporalmente localizável, essa concepção é inadequada.
     Uma outra solução é a que identifica os componentes não-substanciais com estados mentais, impressões de sensação e de reflexão, no dizer de Locke. Essa solução, que já foi chamada de colecionismo fenomenalista, parece ser igualmente problemática, posto que ela também deixa sem explicação as substâncias concretas que constituem o mundo físico(10).
     Uma solução mais auspiciosa seria a que se vale de propriedades instanciadas (property-instances) ou tropos (tropes) como partes, ou seja, de propriedades espácio-temporalmente localizadas, às quais temos acesso experiencial no sentido mais amplo possível, o que inclui propriedades físicas e mentais, simples e complexas. Essa posição, o colecionismo dos tropos, também está aberta a objeções.
     Uma primeira é a de que intuitivamente nenhuma propriedade da substância é parte da substância. Por exemplo: a forma e o tamanho de um objeto material não parecem ser partes de sua substância. Outra objeção refere-se à unidade das qualidades. Considere a coleção dos violetas de uma beterraba, ou a coleção dos sentimentos que tenho ao ouvir uma música. Essas coleções não são substâncias. Como o colecionista pode excluí-las?

     Alternativas plausíveis
     Uma primeira sugestão alternativa para a qual quero acenar começa com o abandono da teoria do feixe de tropos – que combinados parecem constituir objetos materiais, mais do que substâncias – por uma tentativa de encontrar tropos essenciais, necessariamente presentes em qualquer caso de entidade material. Quais seriam eles? A solidez, por exemplo, é comum a todos os corpos materiais. Ela vem acompanhada de certa forma e volume. Mas forma e volume podem variar. Ademais, líquidos como a água de um copo, ou gazes como o ar de um balão, não são sólidos, embora também contenham substâncias.
    Se formos além e buscarmos alguma coisa única e essencial a todas as entidades materiais, a resposta natural é que ela é a própria matéria, definida em física como tudo aquilo que ocupa um espaço (volume). O conceito de matéria está intrinsecamente associado ao de massa (ou de massa-energia), definido pela física como a quantidade de matéria. A massa é em física duplamente definida como a medida da resistência do corpo à aceleração (massa inercial) e como aquilo que produz atração gravitacional em proporção à sua quantidade (massa gravitacional); como essas duas medidas sempre se mostraram proporcionais, elas devem ser medidas da mesma coisa. Pode parecer que esses conceitos de física sejam demasiado distantes do que Aristóteles possa ter tido em mente quando falou de substância. Contudo, devemos lembrar que o senso comum sempre teve implícita a idéia de matéria como aquilo que ocupa espaço e de massa como a resistência dos corpos às forças aplicadas a eles... Isso explica o fato de Aristóteles também ter podido identificar a substância à matéria.
     Só isso, contudo, não basta. É ainda necessário individuar uma porção de matéria de modo a poder distingui-la de outras, introduzindo uma exigência de continuidade de localização. Em outras palavras: a massa precisa ser espácio-temporalmente localizável, e o seu deslocamento, caso ocorra, deve obedecer a certa ordem de continuidade. A substância passa então a ser definida como a matéria continuamente localizável. Com efeito, uma matéria continuamente localizável é um substrato capaz de permanecer através de mudanças. Ela é constatável através de um “atributo essencial”, a massa, que se faz reconhecível através dos tropos a ela associados, como os de solidez, forma, volume... que são acessíveis aos sentidos. Parece que com essa interpretação seria possível resgatar a noção de substância como o substrato último.
     Contra essa sugestão é fácil objetar que quando identificamos coisas no tempo é freqüente que a matéria possa ser substituída sem que o suporte da mudança se modifique, seja ele qual for. Assim, podemos substituir a cabeça de um martelo e, tempos depois, o cabo, e ainda assim dizer que é o mesmo martelo, o mesmo se dando com vegetais e animais que, com o passar dos anos, têm toda a sua matéria corpórea substituída. Neste caso, o que permanece durante a mudança não é mais a substância, entendida como o substrato último, mas a substância entendida como objeto de predicações expondo um tipo de coisa que o objeto material ou o particular continuamente localizado é, ou seja, um martelo, uma árvore, um animal, uma pessoa. Essa última sugestão nos trás de volta à sugestão dos sistemas de tropos. Ela nos afasta da idéia de substrato, mas faz-nos recordar das duas primeiras definições aristotélicas e sugere uma resposta mais satisfatória à questão do que permanece através da mudança(11).


Notas:
1 Aristóteles: Categorias, sec. 5.
2 Aristóteles: Categorias, sec. 5.
3 Aristóteles: Categorias, sec. 5.
4 Aristóteles: Metafísica, VII, sec. 3.
5 Howard Robinson: “Substance”, in Stanford Encyclopedia of Philosophy (internet 2004), p. 5.
6 René Descartes: Discourse de la Methode, cap. IV.
7 John Locke: Essay Concerning Human Understanding, livro 1, cap. XXIII, § 1.
8 Baruch Spinoza: Ethica Ordine Geometrico Demonstrata, Parte I, Definições III.
9 J. Hoffman & G. S. Rosenkrantz: Substance: its Nature and Existence (Routledge: London 1997), pp. 26-27.
10 J. Hoffman & G. S. Rosenkrantz: Substance: its Nature and Existence, p. 29.
11 Um desenvolvimento dessa alternativa encontra-se em David Wiggins: Sameness and Substance (Cambridge University Press: Cambridge 1996, sec. ed.).


ENTREVISTA SOBRE O LIVRO "VIDA EM PENSAMENTO"







ENTREVISTA SOBRE O LIVRO "VIDA EM PENSAMENTO" PARA A SCORTECCI:


Olá Cláudio. É um prazer contar com a sua participação no Blog Divulgando Livros e Autores da Scortecci do Portal do Escritor.

Do que trata o seu Livro? Como surgiu a ideia de escrevê-lo e qual o público que se destina sua obra?

O livro surgiu de um memorial aprovado em concurso. Decidi estendê-lo na forma de uma autobiografia intelectual ao nível de "Busca sem fim" de Karl Popper. Sem falsa modéstia, creio ser a única pessoa no Brasil capaz de escrever um livro com essa ambição.

Fale de você e de seus projetos no mundo das letras. É o primeiro livro de muitos ou apenas o sonho realizado de plantar uma árvore, ter um filho e escrever um Livro?

Vivo para isso. O prazer maior está no ato de produzir algo inovador e razoavelmente relevante. A meu ver é isso o que mais falta à filosofia contemporânea, que se transformou em uma gigantesca e geralmente tediosa Hollywood acadêmica. Quero mudar isso. Para mim a filosofia deve ser em "grand style". Quero escrever as "Bachianas Brasileiras" da filosofia.

O que você acha da vida de escritor em um Brasil com poucos leitores e onde a leitura é pouco valorizada?

Como professor não me preocupo em vender, mas em ser lido por quem me compreenda. Depois desse livro pretendo escrever somente em inglês. Os editores brasileiros não acreditam em filosofia brasileira, nem os leitores brasileiros que conhecem o assunto. E o pior é que meu estilo filosófico não é submisso aos cânones das filosofias anglo-americana, alemã ou francesa, preocupadas como estão em se preservarem a si mesmas, o que torna a assimilação acadêmica internacional difícil, para não dizer improvável. Eles estão preocupados em se auto-preservar, nós em lhes imitar.

O seu livro merece ser lido? Por quê? Alguma mensagem especial para seus leitores?
Meu livro foi pensado como uma introdução opiniosa à filosofia, feita para estudantes. Há muitas espécies de filosofia. Cada qual acredita que uma delas é a boa filosofia. Se você acredita que a minha perspectiva é a mais adequada, leia o livro. Se você acha que uma outra maneira de filosofar é que é boa, então leia meu livro, pois pode ser que ao lê-lo mude de ideia.

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O livro "Vida em pensamento: autobiografia filosófica" foi baseado em um Memorial de concurso para a UFRJ que teve no autor o único candidato aprovado. Ele foi considerado para publicação por se tratar de uma introdução opiniosa a uma ampla variedade de tópicos da filosofia contemporânea. Ele encontra-se acessível sob forma de e-book (ed. Scorteccy) na Amazon e outras lojas virtuais.






sábado, 14 de fevereiro de 2015

##TOWARDS AN UNIFIED THEORY OF TRUTH (draft on the correspondence theory of truth)

ATTENTION: THIS IS A ROUGH NON-CORRECTED DRAFT. The final version will be published as the chapter 5 of the book Philosophical Semantics...  






- 5 -
SKETCH OF A UNIFIED THEORY OF TRUTH


We have got some conclusions from the last chapters: the epistemic meaning of an assertive sentence is its rule of verification, which is the same as a thought (which I will use in what follows in the sense of f-thought); the most proper truth-bearer is the thought; the truth-maker of the thought is the fact referred by it. Moreover, the effective applicability of the rule of verification or thought should be the existence of the fact that satisfies it, paralleling the fact that the effective applicability of the conceptual rule is the existence of the property referred by it.
   However, we also saw that the property of the rule of verification (the thought) of being effectively applicable should have to do with its property of being true, since being true seems to be a meta-property of the thought, of the rule of verification, allowing the reference to the real fact; the properties are at least equivalent. Thus, maybe the property of the rule of verification of being effectively applicable would be the property of the existence of a fact. But this seems to make no sense, particularly when we accept the truism that truth is the property of a thought of corresponding with a fact. Even if it is confirmed that the assertion of the truth of a thought is equivalent to the assertion of the existence of a fact, equivalence isn’t the same as identity: truth and existence may be and seem to be distinct properties, even if they are equivalent properties.
   Although I will come back to this issue at the end of this chapter, I think that the different senses of the word ‘truth’ as it is captured by dictionaries may provide some help to escape from this trouble. If you investigate the senses of the word ‘truth’ in different dictionaries and even of different languages[1], you will see that the word has, along with several secondary senses, where the word can be replaced by truthfulness, authenticity, integrity… two persistent uses that are empathized, which are:

(a)  Truth as consisting in things being as we believe that they are, as conformity with facts, as accordance with reality.
(b) Truth as the real thing or fact or event, the actual state of affairs.

 So, for example, in the sense (a) we say that a statement is true, uttering sentences like ‘Tell me the truth’, while in the sense (b) we say that the fact is true (real, existent) by uttering sentences like ‘We are searching for the truth’ or ‘the mentioned occurrence was true’ or ‘the finding of scientific truths’, or ‘In truth, she respects your work’.[2]
   This ambiguity in my view helps to solve the trouble. Truth in the sense (a) is correspondence; it is the property of thoughts of being in accordance with the way things actually are (facts). If our first methodological principle – according to which we should at least prima facie accept our humble commonsensical and ordinary language views – is correct, then the correspondence view of truth must also be the philosophically central one. In this sense truth is the property of the thought of corresponding with a fact.  But we still have the sense (b) of the word ‘truth’, in which we are speaking of the reality of facts. In this sense truth is the property of the fact of being correspondent with its thought. And if we assume that the thought is a rule of verification, truth is the property of some facts of having their rules of verification (their thoughts) effectively applicable to themselves, what means that truth can also be seen as the property of the existence (reality) of a fact.
    So, it seems that we can accommodate the two ways that we can philosophically consider the truth as due to an ambiguity that lays deep in our ordinary linguistic intuitions, concluding that there are at least two senses of truth, namely, as the property of correspondence regarding a thought, and as the property of existence regarding a fact, both also related by equivalence.
   Finally, if we accept this duality in the most salient senses of the word ‘truth’, we are able to explain why we feel that the world would exist even if no thinking being were here to verify this truth, a problem already tackled as we discussed the ontological consequences of our reconstruction of Frege’s concept of thought. The explanation is as follows: when we say that the world would exit without any mind to think it, we understand truth in the sense (b), as the existence of the fact, we are normally speaking about the existence of the facts constituting the external world; and the existence of a fact is the effective applicability of the rule of verification constituting its thought. This effective applicability of the rule, however, does not demands any actual instantiation of the rule of verification in a mind (it does not demand the actual existence of any rule) but only its potential instantiation. The rule does not need to exist actually. Only the possibility of its existence is demanded. On the other hand, in the sense (a) it would not be true that the world can exist without any mind to think it, since in this sense truth is the property of an f-thought.   
   In order to get more feasible results, in what follows I will reconsider the correspondence theory of truth.

Truth as correspondence
Some would think that the adoption of the verificationism leads to the  rejection of the correspondence theory of truth. As we saw, a statement can be verified in many different ways, as far as it satisfies a multiplicity of different criterial configurations, while the fact corresponding to the true statement must remain univocally related to it as being one and the same. Consequently, according to the kind of verificationism we have proposed, it does not seem possible that what verifies the statement is a fact.
   My view is that this is a treacherous reasoning, and that we come to this conclusion only by searching for correspondence in the wrong place. As we will see, usually the correspondence is not between the thought and the many diverse criterial configurations usually given in sense-perception and able to verify it, but between the content of a thought and a fact (we could also say a factual content), also apprehended by us. The difference is that this apprehension of a fact is often indirect and, when it is by our senses, it is incomplete, since perspectival. This apprehension is the more or less direct inferential result of one or more criterial configuration usually given to us in sense-perception.
   In order to make this suggestion clearer, I need to develop what I believe to be the most adequate and comprehensive form of correspondence theory of truth, which ultimately requires a pragmatic investigation of the dynamic constitution of truth as correspondence. First, however, we need to make clear the structure of the correspondence relation.

The structure of correspondence
Assuming that truth in a privileged sense is the correspondence or agreement between the thought and its truth-maker, the fact referred by it, we need first to have clear each term of this definition. The thought must be the f-thought (as we saw, inherently conceived by means of p-thoughts) expressed by an assertive sentence. The thought is also the, as we already saw, the proper truth-bearer; the fact, the factual content, is what we have analyzed as a combination of elements that serves as the reference of the thought, its ultimate truth-maker in the most proper sense. These concepts we have already explored in the chapter on Frege.
   What we lack is an explanation of the concept of correspondence in its pregnant sense. The chief requirement seems to be that of structural isomorphism between the thought and the fact.[3] This isomorphism or structural identity can be understood in the sense of a biunivocal relation between the concatenated components of the thought and the similarly concatenated components of the fact. Considering only singular sentences, we can say that thoughts expressed by the sentences of the form Fa or aRb, in order to be true, must correspond biunivocally, regarding their components, with the elements of reality composing the respective facts. (We should, of course, not go further, requiring that there must be some G relating F with a, or some S relating R with a and some T relating R with b, under the price of an infinite Bradleyan regress.) The possibility of structural isomorphism – what Wittgenstein called the possibility of structure – is the logical form, which is what must exist in common between the thought and the world, between any representation and what it aims to represent.[4] If there must be a bridge between the thought and the world, it must be logical. For the logic is ubiquitous: nothing cognoscible, and therefore nothing at all, remains beyond it.
   However, it seems that structural isomorphism as explained above is too poor as an explanation of correspondence. Consider, for example, the following sentences:

1.     The book is on the table.
2.     The cat is on the mat.
3.     The cat is under the mat.

   Structurally, the three thoughts expressed by these three sentences have the same form aRb. They are structurally isomorphical with the reality if their components are biunivocally related with the elements of the corresponding facts and the elements of both are similarly concatenated. But is this enough to distinguish them? If by similar concatenation we mean the same logic concatenation, then these three sentences, having the same form aRb, have the same structure and may depict the same fact. The conclusion is that we need something more to explain correspondence.
   I think that there is a way to explain the similarity of concatenation if we pay attention to the ways we identify the components of the thought and the components of the corresponding facts. In other words, we need to include in our understanding of correspondence the criteria by means of which we identify or individualize the elements of the fact in order to make them biunivocally related with the elements of the thought. This can be achieved by means of definitions, for example, by means of the definitions of ‘book’, ‘table’, ‘cat’, ‘mat’, ‘being on’ and ‘being under’ for the examples above. It seems also that what we may call correspondence in terms of exact similarity between a content of thought and a factual content can be explained by the satisfaction of two conditions: (1) biunivocal relation between the elements of each set (including objects, properties and relations); (2) identity in the criteria of identification that we have to each element bi-univocally related with the one corresponding element of the fact. This seems to be all that we can mean by correspondence or adaequatio, since the concatenation follows from (1) and (2). So, if I say, for example, ‘The Moon is white’, what I mean is that the elements ‘Moon’ and ‘white’ in the thought are biunivocally related with the corresponding elements Moon and White in the fact that the Moon is white, and (2) that we have criteria to identify the Moon and its whiteness, following from this the similarity of concatenation between the subject term and its predicate from the one side, and, from the other, between the Moon and its whiteness. Finally, there is an additional factor, namely, intentionality. Truth as correspondence has a directionality from the thought to the fact in the world and not the opposite.[5] In the opposite direction may be a causal factor: the experience of a fact may make us recognize the truth of its thought.
   Assuming this understanding of the correspondence, we can express a static structure in which the predicate ‘…is true’ is identified with the predicate ‘…it corresponds with the fact’, an identification in which both predicates work as semantically meta-linguistic predicates applicable to thought-contents in a way similar to the way in which we say ‘“Themistocles won the battle of Salamis” is a historical statement’. According to this view, for any thought or content of belief p, to say that p is true is the same as to say that p corresponds to a fact. We can express this symbolically using p as the expression of an f-thought, V for the predicate ‘is true’, and C for the predicate ‘... corresponds to a fact’. The predicates V and C apply to p as meta-predicates belonging to a semantic metalanguage referring to the thought-content expressed by p, what can be shown by putting p under quotation marks. Here is the formulation:

(1)  Vp’ = Cp[6]

According to this identification, truth is the property of a thought-content expressed by a sentence p, namely, the property of corresponding with a fact.
   This formulation depends on the application of monadic predicates ‘...is true’ and ‘...corresponds to a fact’. However, monadic predicates can be often unfolded into dyadic predicates like, for example, ‘…is father’ into ‘…is the father of…’. The same can be said of the predicates ‘…is true’ and ‘…corresponds to a fact’, which can be unfolded as dyadic predicates of a semantic meta-language relating the thought expressed by p with the fact or factual content that q like ‘…is true for…’ and ‘…corresponds to the fact that…’ In the same token, one could say ‘“Themistocles won the battle of Salamis” express the same historical occurrence as “Themistokles gewann die Schlacht von Salamis”’.
   This means that the definition above can be explained more thoroughly as stating that for a given thought-content p, to tell that p is true for the factual content q is the same as to tell that the thought p corresponds to or is adequate to the fact of q, understanding correspondence as a relation of identity of contents expressed by p and q, so that we can say that p = q. (I use the ‘_’ under the q in order to show that this content can be also read as a real fact in the world.[7])  Giving a simple observational example: suppose that the thought expressed by ‘The Moon is white’ is true. We do it because of the factual content that the Moon is white. And this is the same as saying that the thought-content expressed by ‘The Moon is white’ corresponds to the content of the observation that the Moon is white, which is factual.
   Now, using the symbol V in the place of the semantically metalinguistic predicate ‘…is true for the fact that...’ and using the symbol C for the also semantically metalinguistic predicate ‘...corresponds to the fact that…’, we have the following formalized version of a more complete definition, in which the thought-content expressed by p and the factual content expressed by q are being metalinguistically related by the meta-predicates V and C:

(2)  ‘p’Vq’ = ‘p’Cq

   Indeed, if (2) is an unpacking of (1), this seems to be the right way to formulate it. According to the identification (2), the assignment of truth is the same thing as the assignment of the relational property of correspondence, that is, the exact similarity of the thought-content with the factual content – a similarity of content that should be analyzed in my view in terms of structural isomorphism plus the criteria of application of the component terms in their composition.

Paradoxes of self-referenciality
Although limited, the identifications we have made already enable us to deal with paradoxes of self-referenciality. They preserve the analogy between existence and truth: in the same way as the existence is a property of concepts, truth or correspondence is a property of thought-contents or f-thoughts or propositions expressed by entire statements. Because of this, sentences like ‘“2 + 3 = 5” is a true statement’ and ‘“2 + 3 = 6” isn’t a true statement’ are grammatically correct and express correct attributions of truth, while self-referencial sentences like:

   This statement is true,
   This statement isn’t true,

aren’t grammatically correct and cannot correctly attribute a truth-value to a thought. One cannot say that they are wrong only because they are self-referential, for there are self-referential sentences that have truth-value as ‘This statement has five words’. The problem is that, since the attribution of a truth-value, being a meta-predicate, cannot be a constituent of the thought, this attribution cannot belong to the content of thought. In the sentences above, however, the attribution of a truth-value is presented as a thought-constituent. The same applies to indirectly self-referent statements like:

   The next statement is false… The previous statement is false.

   In this case one tries to apply the predication of a truth-value indirectly to the same statement of the beginning by making through it a second statement – which says that the first statement is false – false. But in this case if the first statement is true it must be false and if it is false it must be true. The paradox is again generated by the fact that the predication of a truth-value is treated as a constituent of the statements, which are indirectly self-referential instead of meta-predicative. The circularity results from the fact that truth cannot play a role as a constituent of a thought-content in the same level as the others: truth is a meta-property of a complete thought-content, not a property of it. It is, one could say, an external, not an internal property of an f-thought.


 Speaking of truth as the effective applicability of a rule of verification isn’t any internal property of this rule, but something that is added to the rule being independent of it.

The pragmatics of the correspondence relation
According to the view I wish to defend here, which is influenced by Moritz Schlick’s short defence of the correspondence theory of truth[8], which in my view was influenced by some central ideas of Edmund Husserl[9], the correspondence has a dynamic or pragmatic side that deserves to be explored. Very often we can establish an idealized sequence with three successive temporal steps: (1) a suppositional, (2) an evidential and (3) a conclusive step. Together they form a very common form of verificational procedure.
   The best way to explain this is beginning with a very simple example. Suppose that I ask myself: ‘Will it rain in Natal tomorrow?’ This is the suppositional step. Now, imagine that tomorrow comes and I go out of my home and I see that it is really raining. This is the second, evidential step. Once I do this, I compare my earlier question with the observational evidence that it is raining, and I conclude that the content of the question is the same as the content of my observation and that, therefore, they agree – they correspond. And this is what can be meant with my judgment that it is indeed true that it is raining. Certainly, I could make this question tomorrow, as a hypothesis, soon after hearing some drops of water on my cellar, or I could have seen the weather forecast today telling that (probably) would rain in Natal tomorrow.
   Examples like this can be multiplied. A student has hear that another student, who isn’t very applied, has achieved a better result; he doubt this; then he asks the teacher if this was the case (the teacher has here a testimonial function). A notice is transmit in the TV informing that a nuclear test was made in some place of the earth… and this information is later confirmed by the responsible authorities (again a case of testimony). A similar procedure, as we will see, applies also to non-observational truths. But for now, restricting myself to perceptual judgments, I can say that at least for many cases we can formulate the following action’s schema with four steps:

1)    The suppositional moment: the realization of a supposition, hypothesis, conjecture, guess. In this moment, we ask ourselves whether an f-thought is true, if the rule of verification that constitutes it is effectively applicable. We can express this as ‘I suppose that p’ or ‘it is possible that p’, where p expresses a content that can be perceived. This step can be formalized as ‘?p’. This supposition is made within some linguistic practice, within some context.
2)    What follows is the evidential or perceptual (or procedural) moment: the realization of perceptual experience, under determined circumstances of observation, which has the potential of corresponding to the content of the supposition.
This is the way by means of which we try to verify the truth of the supposition finding its perceptual correlative; in the case of observational truths this step is very simple. We look for an expected adequate thought-content that, in an adequate context, we simply accept as a truth-maker which can be rendered as ‘I have the perception of p’, call it ‘!o’ (phenomenologists call it registration or fulfilment).[10] As we will see, there is no question about the truth-value of o: It is not an ‘evidence’ or ‘certainty’ in itself, but it is stipulated as such by means of the context or practice or language-game or linguistic system in which it occurs.
3)    Confrontational moment:  comparison or confront between the suppositional content and the perceptual experience, what will allow the verification or falsification of the content of the supposition.
Here we ask whether the supposition matches the evidential result of the procedural step. In the case of perceptual experience that we are considering, we ask ourselves whether the thought-content of the hypothesis is like the thought-content given to us. Being both sufficiently congruent, this means that there is an agreement between both. In the case of a perceptual experience the positive answer can be summarized as p = o. It can also be that the thought-content expressed by the hypothesis shows to be different from the factual content given in the contextually expected sense experience. In this case: p o. In the practice it is possible that more than one perceptual experience is carried out and in more than one way, but we are considering the minimal conditions.
4)    Judgemental result: Finally, in the case in which p = o, the thought expressed in the supposition will be accepted as true, otherwise it will be rejected as false. When p = o, there is correspondence and the conclusion is an affirmative judgement that can be symbolized as ├p. In the case in which p ≠ o, that is, when there is no correspondence, the thought is false, what can be expressed be the judgement symbolized as ├~p.

We can summarize these four moments of the whole verification process regarding the achievement of observational truths of the kind considered above in the following temporal sequence:

?p, !o, p = op

This analysis shows that correspondence usually is made between some suppositional thought-content and some perceptual content that is stipulated by the linguistic practice in which is given as beyond doubt.
   It is also worth to notice that the standard state of ├p has the form of a report that is settled and rested.[11] However, it can be always questioned again. In this case, new verifying procedures can reconfirm the judgment or detect some inadequacy.    
   What we presented is what we may call an anterograde way to get the truth, since we’ve got here temporally from the hypothesis to the observational evidence that confirms the hypothesis by being identical to it. However, the opposite direction is also possible. We can also have a truth resulting from the perceptual experience or observation, progressing from the evidence to the hypothesis – a way to achieve truth that we may call retrograde.[12] For example, I open the door of my home with the intention to go out and unexpectedly see that it is raining. I come back to look for an umbrella with the obvious conclusion that it is raining. In this case the perceptual evidence comes first. But it seems that the recognition of truth does not belong to the perceptual experience as a direct product of it, since one can see the rain without taking account of it. I think that here we can explain the process of getting the truth included in the judgment of the given example in the following way. First we have the observational experience o! Then (still during or after it) we make the supposition ?p, that is, we direct our minds to a certain interpretation of the experience by recalling our memory of (linguistic or not) conceptual experiences. And finally we answer the supposition appealing to the evidence that has been given: we see that p = o. This is what brings me to the conclusion that it is true that it is raining. We could give to this process of retrograde achieving of truth the following sequential formulation:

!o, ?p, p = o /├p

   A common case of retrograde awareness of truth takes place when someone has one unexpected sensation. If I awake with a pain in my arm, first I feel the pain: !s; then I consider cognitively if it is pain in my high arm ?p, and, since I identify s with p, I conclude that I have pain in my arm: ├h.
   The two cases we have considered until now are the simplest ones. The dynamic view of correspondence can be extended to the truth of non-observational, mediated thoughts. Suppose that Lucy is in the airport Charles de Gaulle in Paris, ready to take a flight to Dakar. The flight time is of approximately five hours. She calls her daughter, who lives in a farm in the Senegal and asks her if the weather in the city of Dakar is good; this is ?p. Suppose that her daughter affirms that the weather in Dakar is and will remain good and warm enough. There is no significant reason for doubting this information, which she takes as giving her the appropriate evidence. The thought !q that she had when she asked about the weather in Dakar is the same as the thought belonging to the question ?p. Consequently, since p = q, she concludes that p is true, that the weather in Dakar is good. But the thought in !q is not an observational thought. It is the result of testimonial inferences that are unknown to her, maybe based on some kind of observation of the weather conditions in Dakar. In this case, putting ‘<<<’ in the place of some chain of reasoning unknown to her that leads to !q, and ‘!o’ to the observational thought(s) that in some way have originated !q (similar to those that she will have when she arrives in Dakar after some hours), we can formalize the verification process in which p is presently made true for her as:

?p, !q (!q <<< !o), p = q/p

Important to note is that the evidential character of the observation !o is preserved in the supposed inferential chain, being transmit from thought to thought until the conclusion !q, which inherits its evidential character.
   The foregoing example is of anterograde verification, beginning with one hypothesis and ending with the comparison between the hypothesis and a derived evidential thought content. However, we also may have a retrograde procedure with a chain of reasons that ends with the match of a derived evidence with a supposition. Suppose that another person take the same fly and that the commander informs her that the weather in Dakar is and will remain good… The person will be brought to the conclusion that the weather in Dakar is in fact good by means of another indirect and for him unknown evidential chain. In this case it is the evidence that produces the questioning reaction that is answered by means of a comparison of contents, from which the final judgment that the weather in Dakar is good results. This process can be summarized in the following sequence:

!q (!q <<< !o), ?p, p = q /p

We see again the difference between anterograde and retrograde verification. We may guess whether the intuitions of a researcher who still does not know how to proof some hypothesis, but has a glimpse on its truth, depends on the unconscious awareness that the knowledge of the factual content expressed by !q is or may be derived from evidential observations or postulates.
   Also the general belief – universal and existential – can be explained in this way, as the identity between the contents of the hypotheses and the contents of sets formed by the respective conjunctions and disjunctions of factual contents, often resulting from inductive inferences based on observational facts. So, suppose that ├p is the assertion: ‘All the books in the shelf of my room are in English’. This generalization can be derived in a retrograde form from my casual observations o1, o2on, of each book in the shelf as follows:

{!o1 & !o2& !on } → !q, ?p, p = q /├ p

   Of course, I can also first ask myself if all the books of my shelf are in English, and after looking each one of them to conclude that this hypothesis is true in an anterograde procedure:

?p, {!o1 & !o2& !on } → !q, p = q /p

   As the former, this example is of a deductive general conclusion, but it is easy to see that inductive generalizations should also have not very different structures.
   There are other cases to which I wish to give only cursive solutions. One of these is the case of auto-psychic truths. I know the truth of p: ‘I have headache.’ The correspondence seems to be as follows. First, I have learned interpersonally how to identify the location of pain, and by inductive exclusion the kind of feeling that I have when I have a pain; this learning can be applied to pains in the head. Second, when I have the headache, there is a feeling of pain first: !s, and then comes ?p, the actualization of the memory of the feeling called pain associated with the words, followed by the identification p = s, and the conclusion ├p:

!s, ?p, s = p / ├ p
Wittgenstein had an expressivist explanation for such cases; for him h = ‘I have pain’, which is nothing more than the replacement of a natural expression of pain like ‘Ouch!’.[13] In this case, our schema would be simply ‘!s h’ without correspondence. But this could be the expression of a more direct reaction that turns to be true only after the previous more elaborated process.
    Another interesting case is that of true conditionals. Consider the statement ‘If John were the president of USA, he would be famous’.[14] The objection is that there is no fact to make this sentence true. The answer is easy. Although there is no possible fact to make the sentence true, this is not required. What the sentence requires is that there is a possible fact to make the sentence true, and the sentence is true because if it were the case that the antecedent is true, that John is the president of USA, it would be also the case that the consequent is true, that he would be famous. We can express this using the language of possible worlds. We can say that there is a (merely) near possible world in which Peter is the president of USA. Since in our world all presidents of USA were (even I for a short time and not for the best reasons) famous, we can infer that in a near possible world in which USA exists, the presidents of the country are famous. Since Peter is the president of USA in one of these near possible worlds, it is a fact of one of these near worlds that he is in this reign of possibilities famous. We conclude that if Peter were the president of USA he would be famous because the sentence corresponds with the fact, even if it is not a fact in our world, but in a possible world, that is, a supposed fact under a supposed circumstance that we are able to imagine.
   Another point is that we have understood the f-thought as a rule of verification. How would all these f-thoughts as rules of verification fit with our schemas? This is a question that we will let to be answered later.

Generalization to formal sciences
Similar structural and dynamic forms can be found in the formal sciences, allowing us to generalize the correspondence theory to a domain traditionally occupied by the coherence theories of truth. Suppose that we want to demonstrate that the sum of the angles of a triangle is 180°. We can do it first by suspecting that this could be the case: ?p. Then we search for a proof. We can trace a straight line that touches one of the vertex of the triangle, so that this line is parallel to the side opposed to this vertex. Since the three juxtaposed angles formed by the parallel and the triangle are the same as the internal angles of two opposed vertexes of the triangle plus the angle of the first vertex, and their sum is necessarily180°, we conclude that the sum of the internal angles of this and indeed any Euclidean triangle must be of 180°. This conclusion is the evidence !q. Since we see that the content of !q is the same as the content of the hypothesis ?p, we conclude ├p. Using ‘a’ for axioms, the form of this anterograde procedure could be rendered as:

?p, (!a>>>!q), p = q, /p

   Now one example from the arithmetic: we can prove the statement (i) ‘2 + 2 = 4’ in a Leibnizian manner. We begin with definitions (which are equivalent to the basic perceptual experiences in empirical sciences). First, we define 2 as 1 + 1, 3 as 2 + 1, and 4 as 3 + 1. We call this set of definitions d. Replacing the numbers 2 and 4 by their definiens in the statement (i) we get ‘(1 + 1) + (1 + 1) = (3 + 1)’. Since 3 is defined as 2 + 1, and 2 as 1 + 1, 3 can be replaced by (1 + 1) + 1. Replacing the 3 by this result in (i) we get: (1 + 1) + (1 + 1) = ((1 + 1) + 1) + 1), which proves that 2 + 2 = 4. In this way we derive the confirmatory evidence of the hypothesis !q, which is ‘2 + 2 = 4’; this confirmatory evidence serves to check the hypothesis !p that 2 + 2 = 4. Again, abbreviating the definitions as ‘d’ we have the following anterograde verification:

?p, (!d >>> q),  p = q /p

   We see again that the evidential content of !q, which serves to check the hypothesis ?p that ‘2 + 2 = 4’, is not the same as the definitions of 2, 3 or 4. It is the same as the result of a reasoning that we make from them, a reasoning that derives from the definitional character of its premises. This result expressed by q is the geometrical fact that corresponds with the supposition ?p making p true.
   Finally, we can give examples concerning logic. Consider the following theorem of modal logic: ‘P → ◊P’. This can be seen as our hypothesis ?p. How to prove it? In the S5 modal system we can do it making use of the axioms AS1, ‘◊ P ↔ ~□~P’ and AS3, ‘□~P → ~P’ as assumptions. With this and with the help of the rules of propositional logic, we construct the following anterograde proof of the theorem:

     The hypothesis is: ?p, where p = (P → ◊P)

     The proof:
1       □~P → ~P             (AS3) (taken as evidence)
2       ~~P → ~□~P         (1TRANS.)
3       P → ~□~P             (2DN)
4       ◊P ↔ ~□~P           (AS1) (taken as evidence)
5       ~□~P → ◊P           (4 ↔E)
6       P → ◊P                  (3,5 SD)

     Now, (P → ◊P) = !q, and since p = q, we conclude that p is true, we conclude ├p. Using our abbreviation we get the following anterograde form:

!p, (!a>>>!q), p = q,├ !p

   Since the logical fact !q, which carries with itself the evidences derived from the axioms, expresses the same thought-content as the hypothesis ?p, we conclude that there is a correspondence, that p is true, that ├p. (Also interesting is that in the case of logical facts we does not need to underline a or q: there is no need to distinguish between the conceived and the real fact.)
   Of course, the retrograde form could be also found regarding any of the three above exemplified cases. Considering only the first case, suppose that someone draws a straight line that touches the vertex of a triangle, being this line parallel to the opposite side. This person could easily be lead to see that this triangle and in fact any Euclidian triangle would have 180°. In this case we would have the following retrograde verification procedure:

!q, (!a >>> !q), ?p, p = q, /p

I suppose that this could be the case when a mathematician or a logician has the insight of a certain theorem as being true. The upshot is that the procedures whereby we show the correspondence of formal truths are structurally analog to the procedures whereby we show the correspondence of empirical truths.

Why analytic truths are called true?
Finally, we can apply a similar procedure for the so-called analytical sentences, showing that they are also called true because of correspondence, even if this is, as we will see, a limit-case. It is possible to say, for example, that the analytical statements ‘It is raining or it is not raining’ and ‘Singles are non-married’ are true because they correspond to the respective facts that necessarily either it is raining or not, and that it isn’t possible that an adult single man can be married. What entitles us to say this?
   Now, understanding the analytic propositions such as those that are true by means of a combination of the senses of their component expressions (pace Quine), what are the facts that make true analytic sentences as

(1)  Either it is raining or it is not raining,
(2)  Bachelors are males,
(3)  A triangle has three sides,
(4)  A material body must have some extension?

   Surely, these sentences are tautological: there is no fact in the world able to make them false. However, we could still say that they are made true by facts. Sentence (1) is made true by the logical fact that ‘j ˅ ~j’ (the law of the excluded middle) that is inbuilt in it. Sentence (2) is made true by the fact that a bachelor is conventionally defined as non-married adult male. Sentence (3) is made true by the fact that a triangle can be defined in the Euclidian geometry as closed plane figure with three sides and three angles. And sentence (4) is made true by the fact that it is part of the definition of a material body that it has some spatial extension. These are conceptual facts. We are enabled to speak in this way, redundant as it seems. And we can summarize the process of self-verification of these statements in the same way as we made with the statements considered in the last section. Thus, in the case (1) we can begin with the question ?p1 = ‘is it raining or not?’, and we realize right away that the sentence has the same structure as the principle of the excluded middle or ‘j ˅ ~ j’, which can be symbolized as the logical truth or fact !q1 and can be proved to be true by means of a truth-table. This is enough to make p1 true because, independently of the senses of the constituents of p, one can see its logical structure as warranting its truth. We can summarize this correspondence in the same way as in the cases of the last section:

?p1, !q1, p1 = q1 /p

We could say that this thought corresponds with a logical truth, that it is self-verifying, that it is a limiting case of correspondence.
   In other cases some reasoning may be necessary. In the case (2) the suppositional moment ?p2 = ‘Is a Bachelor a male?’ To verify this we need first to look at the definition of bachelor as a point of departure: !d = ‘A bachelor is an unmarried adult male’. From !d we can infer !q = ‘A bachelor is a male’. Summarizing in a retrograde verificational procedure, we get:

 ?p2, !d2!q2, p2 = p2 /p

We see that even in the case of analytical thoughts, it makes enough sense to speak of correspondence. And the reason is made clear in the last case. Even in the case of self-verification, the procedure isn’t necessarily redundant and transparent, often demanding some amount of reasoning.

Coherence as a mediator
That truth has to do with coherence is patent. If someone says to us ‘John stop to breath for two hours as he was asleep last night’ we will say that this statement is false, not because we have made some verifying observation, but because it is incoherent with our belief-system, particularly with its scientific dimension. But as a theory of truth, affirming that the truth of any proposition resides in its coherence with our belief-system, the concept of coherence is problematic. Perhaps the most embarrassing problem is that of circularity.  The concept of coherence is that of inductive and/or deductive relationship between propositions (what involves the weaker concept of consistence[15]). However, the concepts of inductive and deductive inferences (as much as that of consistency) are defined by means of truth. An inductive inference is the inference that makes a conclusion probably true, given the truth of its assumptions, while the valid deductive inference is the inference that makes its conclusion necessarily true, given the truth of its assumptions. Hence, the coherence theory defines the truth of any statement j  as its coherence with a set A of thoughts, so that the coherence is always dependent on the assumption of the truth of one or more thoughts that cannot be established by coherence alone, except in a circular way.
    My view of coherence enables us to circumvent this difficulty, since in the understanding of coherence that we wish to propose the coherence enters as a complementary dimension of the correspondence theory, namely, as the capacity of transmitting the truth in a network of propositions, beginning with those that are based on some formal or empirical (psychological or perceptual) established evidence, allowing us to finally grasp some factual content that shall make some thought true without the need of experiencing this factual content, either as a correspondingly formal axiom or as an evident perceptual content. For example, we know that the statement ‘John was breathing as he was asleep last night’ is true, and that it is true because it corresponds to the factual content that John was breathing during his sleep, and grasp to this factual content as the result of coherence, that is, as the result of inferences derived from our system of beliefs, inferences that transmit the ‘veritative force’ from the one thought or belief to the other. But this veritative force comes from our perceptual experiences, of our knowledge of biological laws, etc.
   We begin to see that, even if coherence cannot be understood as a definition of truth, it can be understood as a mediating procedure whereby the correspondence is obtained. The modal proof of ‘P → ◊P’ does not come directly from AS1 and AS3, plus some rules of propositional logic. We have some deductive inferential steps, and these steps are what constitute the coherencial moment of the procedure, which many coherentists erroneously saw as the proper criterion of truth for the formal sciences. In the present case coherence is constituted by material implications, but, as we already noticed, it includes inductive inferences in the case of the verification of empirical thoughts.
   This latter case can be better illustrated by two examples, which teach us something important about the relationship between coherence and correspondence. First, suppose that a gift is anonymously sent to me. I open it and see that it is the book The Cloven Viscount, from Italo Calvino. I wonder if Silvia has sent it. I know that I presented Silvia with a copy of the book The Invisible Cities by the same author and that she told me that The Cloven Viscount was a funny book. But Silvia lives in Rom and the present das been sent from Rio de Janeiro. So I realize that this book could have been sent from somewhere else. But then I remember that Silvia could be back in Rio de Janeiro, a city where she lived most of her life. An advocate of coherence theory of truth would say that the proposition p ‘My friend Sylvia sent me a copy of the Cloven Viscount’ is made true by its coherence with other propositions like r = ‘I gave an exemplar of The Invisible Cities for Silvia’, s = ‘Silvia told me that The Cloven Viscount is a funny book’, t = ‘Silvia’s gift could have been sent from Rio de Janeiro’. The belief in p is probably true because it is inductively inferred with the beliefs r, s and t.
   However, what we really have here is an indirect procedure of verification of the correspondence via coherence. I can assume that I have started with the hypothesis ?p. The beliefs r, s and t together make inductively probable the conclusion !q, namely, ‘Sylvia has sent me an exemplar of The Cloven Viscount.’ But since I see that p = q, I am allowed to conclude that the thought expressed by p corresponds to the thought expressed by q, namely, that p expresses a true f-thought, that p. But it is important to note that  this conclusion is due to the coherence of p with the propositions r, s and t, that is, r & s & t make q inductively probable, what makes me to conclude the supositional thought expressed by ?p corresponds to the factual reality expressed by !q. It is important to note that the second term of the correspondence in this case, as in the most ones, presents itself to our minds not as an observation, but as the result of a reasoning having as assumptions thoughts or beliefs that are directly or indirectly grounded on some kind of perceptual experience.
   Now we could ask what comes first: correspondence or coherence? Is the coherence dependent on the correspondence or, on the contrary, the correspondence is dependent on the coherence, as coherentists would prefer. The answer is that coherence would be independent of correspondence at least if thought-contents could get their probability independently from any point of departure in the axioms of a formal system or in the self-sensory or sensory-perceptual experience. But this is not the case. The thought-contents expressed by r, s and t either describe a perceptual thought (r: she gave me the book…) or a testimonial thought (s: she said me…) based on personal experience (she read the book…) or a deduction (s: she may be back in Rio…) from testimony (as I met her in Rom she told me she lived in Rio…). That is: in the end what is given to me is the indirect product of the correspondence of thoughts with empirically observed factual contents. And these are the ones who guarantee to me q as the derived evidence that would express the fact that Sylvia has sent me the book. This guarantee of q, in turn, is what makes the thought of p true for me. Coherence takes a part in the process. But it would have no force if it weren’t at some point based on perceptual experience taken as evident, in the case of empirical truths, and on axioms or postulates, in the case of formal truths. Indeed, any fairy tale can be coherent and it will not gain any truth with the increase of coherence, since it is not grounded on any sensory-perceptual experience.
   A second example concerns the verdict of a judge. It is well-known that judgments of crimes can only rarely receive direct perceptual testimony from bystanders; because of this they are often coherencial. This was also the case of the American pastor David, who shortly after his marriage with Ms. Rose was interned into a hospital with severe abdominal pain. Since the exams have shown a high amount of arsenic in the blood of reverend David, which we abbreviate as r, the following question was posed: ?p = ‘Ms. Rose tried to poison Reverend David?’. This supposition was later confirmed by the following further evidences:

s: Ms. Rose had the habit of preparing soups for her husband, taking them even to the hospital.
    t: Traces of arsenic were found in the pantry of Ms. Rose’s house.
u: The bodies of the first three husbands of Ms. Rose, with have been all died from unknown causes, were exhumed, with the surprising discovery of a large amount of arsenic in their hairs.

We can now build the following verificational process:

!r > ?p, {!r & !s & !t & !u} ~> !q, p = q, /p

   Certainly, the conjunction of the statements r, s, t, and u is what by inductive inference assures us !q as stating a factual content (that she tried to poison her husband), which confirms our suspect expressed by !r. But a crucial point to be noticed is that the statements r, s, t, and u are all made true by corresponding with perceptual factual contents publicly observable. Again, what this shows is that the coherence view of truth cannot stand alone. The plausibility of q is coherencially grounded on the conjunction of the observational statements r, s, t and u; but they are true because of their correspondence with observational contents, even if they also have theoretical assumptions. And coherence cannot originate truth, since the inductive and deductive coherence relations are defined as ways of preserving and not achieving truth, begging in this way the question. We conclude that coherencial relations work only like the wires of an electric power grid: even if they are not able to generate the energy, they are able to transfer it. We see that coherence is not an independent mechanism, but only an interdoxal mechanism by means of which the correspondence makes its way. Coherence transfers the truth-force generated by the correspondence of contents of more basic beliefs to the derived ones, those acting in the interior of the belief system, in order to produce the content of thought expressed by q, which is accepted by us as evidential, corresponding with the proposition p when having the same content, what means the same as making ?p true. This is why we can also say that the statement p is true because it corresponds to the fact that Ms. Rose has poisoned the Reverend, but that we know about this fact indirectly, from the consistency of the hypothesis with other contents that correspond with the facts that have been observed by us. This thought q, we could say, also expresses what we are sure to be a fact, namely, the fact that Ms. Rose tried to poison reverend David. It is by being involved in the correspondence that coherence is involved with truth; again, coherence is just an interdoxal mechanism by which correspondence takes place.
   A question that remains open is about the status of q. It is the expression of an thought-content, but it is also the expression of a factual content, and we have said that a real fact, the real factual content is the same as an effectively applicable verification rule. Can these different things be reconciled?

What about the truth of the truth-maker?
One of the most serious problems for the correspondence theory of truth concerns the infinite regress that treats the truth-makers, the evidences that verify the hypotheses. We can pose it in the form of a dilemma: Either the evidential content can be doubt or not. If not, it seems that we fall into dogmatism, according to which normal sensory and perceptual truths are beyond any possibility of being false, the same being the case to formal evidences. But this would not be in conformity with the fallibility of our experience; we cannot be absolutely sure about the evidence of any empirical contents; and even formal axioms are also the result of the arbitrary choice of a formal system against others. Now, if the evidential content can be doubted, it seems that we need to look for a new evidential content, identical to what we have considered, which would warrant its truth; but, since this new content isn’t also beyond doubt, it should also be warranted, and so indefinitely. If this regression cannot be stopped, we have no way to ground our supposed truths.
   Restricting myself here to empirical truths, I think that the answer to this dilemma can be found when we consider examples in sufficient detail. Consider the following example of an observational sentence o: ‘There’s a dolphin swimming in the sea’. The truth of this sentence depends on the observation of a Dolphin coming on the water from time to time, an observation that can be interpersonal. The procedure has the retrograde form:

!o, ?p, p = !o/├p.

But this does not mean that o, the given evidence, is absolutely warranted. It can be defeated. Suppose, for example, that in order to entertain the tourists, a diver swims with a rubber dolphin stuck on his back, coming up from time to time in order to produce in the bathers the illusion that they are seeing a dolphin. In this case the evidential content !o that should ground the verification of ?p will turn to be simply false.
   However, the answer of the problem isn’t so difficult. An evidential content doesn’t need to be absolute because it is always postulated as a factual content (as the truth-maker) under some context or practice or language-game that presupposes appropriate circumstances that characterizes the practice and excludes abnormal circumstances. Thus, under normal circumstances in which people are looking the see from the beach during the day, circumstances given in a practice that we may call A, we postulate that the observational content ‘I am seeing a dolphin that just emerged from the water’ is an unquestionable evidence expressed by !o, that is, a matter of fact. In this practice, all other things remaining the same, seeing a dolphin is undoubtedly accepted as the truth-maker of the hypothesis ?p. Since o has also an internal phenomenal content, we could say that in this case the postulation is that the content of o (‘We are having the experience of seeing a dolphin emerging from the water’) can be seen as the same as the fact given in the world (‘A dolphin has just emerged from the water’), that is, the rule of verification of the statement in its effective applicability. But this practice assumes normal or appropriate circumstances under the condition of a ceteris paribus. This means that we can imagine contexts or practices in which the ceteris paribus condition is not present and the supposed evidence is defeated. Thus, suppose that there is no real dolphin in the ocean, but that there is a diver swimming under the water with a rubber dolphin stuck on his back, and rising sometimes near to the surface in order to give the tourists the impression that there are seeing a dolphin… What we have here is a different observational practice B, with abnormal background circumstances, in which experiencing the sole vision of a dolphin emerging from the water cannot anymore be postulated as the same as seeing a dolphin. Under the circumstances posed by a observational practice in which there are rubber dolphins being cared under water, to observe a real dolphin would certainly require a close and more much careful examination, for example, an underwater inspection that we could call o’ and that would be postulated as the evidence in the circumstances of B. In this practice, seeing a true dolphin in order to verify the proposition p could be formulated as:

!o’, ?p, p = o’ /├p.

   We see that our evidences are postulated as absolute, but only relatively to some practice in the case some observational practice that only works assuming its usual circumstances and assuming the exclusion of any defeating evidence. If we get the information of a different background of circumstances able to suspend the assumed practice, the postulation of absoluteness, of evidence, of certainty, vanishes. In sum: what we call perceptual evidence is context-relative.
   Another similar example can make the point still clearer. A person is in a desert and is victim of mirages. Firstly she believes that the lake that she sees in the horizon is real. But soon she sees that it is a mirage caused by unusual atmosphere circumstances. These unusual circumstances invalidate her usual interpretation of sensible content. The normal background circumstances are here being replaced by unusual circumstances that are able to defeat the normal perceptual evidence. The person has learned that the unusual circumstances invalidate the rules of the usual observational practice, so that instead of saying (i) ‘I see a lake in the horizon’ the person says (ii) ‘I see the sky reflected in the horizon’. What was evidence is now seen as false and is replaced by new evidence, which is that of the sky reflected in the horizon. It is important to note that the content of perception in both cases is the same. But the interpretation we give to this content, as a factual content, is very different, and it is different because the surrounding circumstances are able to defeat our normal interpretation of the visually given content. We could also say: the rule of verification of (i) is substituted by the rule of verification (ii), which is effectively applied and therefore inferred as applicable.

The objection of a linguistic circle
Perhaps the most important objection along these lines is the so-called problem of the linguistic circle: propositions can only be compared with propositions, and by comparing hypothetical propositions with evidential contents, even if taken as certain, we would remain trapped inside of language; even if we find the strongest evidences, they would be inevitably intra-linguistic contents and not real facts or states of affairs in the world… Here again, we would be in danger to fall into a reduction to infinite, having as corollary epistemic scepticism.
   A general remark against this objection is that in order to say that we are trapped into an intra-linguistic world of propositions we are already assuming that we know the existence of an extra-linguistic external world, a knowledge that remains to be explained. Moreover, echoing Moritz Schlick’s view, A. J. Ayer gave to the objection of the intra-linguistic circle the following answer:

We break the circle by using our senses, by actually making the observations as a result of which we accept one statement and reject another. Of course we use the language to describe these observations. Facts do not figure in discourse except as true statements. But how could be expected that they should?[16]

Ayer’s argument constitutes in a strong appeal to common sense. Despite of this, it seems to contradict another persistent idea, which is also commonsensical, namely, that the content of the perceptual experience should be some kind of belief-content, which should be something mental from nature, what means that we would never have direct and unquestionable access to things related to perceptual thought – the external facts as they are in themselves.
   One reaction to this argument would be to accept idealism. But idealism is a forbidden solution. Idealism defends that all reality is in some way or other mental; but the concept of mental is relative to its opposite, the concept of physical, in a similar way as the concept of above is relative to its opposite, the concept of under, the earlier to the after, etc. If there is no under, there is no above, without the earlier we have no after, and in the same token if there is no physical, there is no mental altogether. If we take the natural language seriously, that is, if we remain on the side of the guiding methodological principle of all this book of do not reject common sense truths without very good reasons, idealism remains an anathema. So I prefer to preserve the opposition between the mental and the physical by proposing something different, namely, that the perceptual contents have a kind of Janus face. They can be considered in two ways, in a psychological or in a physicalist way, as follows:

(A)                       In a psychological way the content of perception is interpreted as a sensory content internal to the mind, or,

(B)                       In a physicalist way the content of perception is interpreted as an observational content independent of ourselves (s-properties and their combinations).

   In the psychological sense (A) the perceptual contents are what we could call sensory contents. However, the same perceptual contents can be also interpreted in a physicalist sense (B), as what we could call observational contents, that is, as s-properties and their combinations (or as tropes or bundles of tropes).
   This duplicity can be reminiscent of the neutral monism, the doctrine according to which the world is constituted by a neutral stuff, which in at least some cases can be interpreted in a double way, in a physical way and in a psychological way. So, according to Bertrand Russell, who was for some time a defender of this view, our percepts can be interpreted in a psychological way when situated in a psychological context and arrangement and causal relations, but these same percepts will be physically interpreted when they are situated in a physical context and arrangement and causal relations.[17] This is not, however, the way I understand the double interpretation of perceptual contents I am proposing, first because I find the idea of an unknowable neutral stuff superfluous, secondly because in accordance with our principle of established knowledge (like nearly all our contemporaries) I remain a materialist or physicalist. Third because the physicalism fits with our tropism: even agreeing with the idea that the cognitive achievement of our world begins with the s-properties given to the senses, I may defend that in its ontological structure our world is fundamentally built on physical s-properties.
   I can illustrate the duplicity in the interpretation of perceptual contents without relying on any neutral stuff by comparing them with the duplicity of the objects that we see through a looking-glass. What we see in the looking-glass can be interpreted as (A) a simple image of things, for example, of a vase of flowers. But it can also be seen as (B) the vase of flowers in itself. I can, for example, point to the object through the looking glass and you can ask me if I am pointing to the real object or to its reflected image. The difference is given by the context: the image isn’t real; one cannot touch it, one can change its size by approaching the vase to the looking-glass, and the image remains circumscribed into the looking-glass. The real vase of flowers, on the other hand, can be touched, its size will be seen as remaining always the same independently of the size of its image, it will not be circumscribed into any frame, etc. However, the visual internal relations between the image of the vase of flowers and the real vase of flowers will remain the same. 
   This suggestion is reinforced when we consider cases of illusions in which the psychological content is disconnected from its physicalist counterpart. For example: when I put my index finger on the apex of my nose I see my finger duplicated, but I do not say that I see two fingers. Why? Because ‘seeing’ is a verb referring to what is really given in the world, what I called observational (instead of ‘sensory’) content. For this reason I can say that I see only one finger, though duplicated. My observational content is of only one finger. But at the same time I can say that I have the sensory experience or the visual images of two fingers. Now, if I back off my index finger to the distance of 50 cm of my nose, the sensory content (the visual image) and the observational content collapse into one only experienced content of my finger, so they cannot be distinguished. Though I may be aware of the double way the perceptual content can be interpreted here, I cannot distinguish them.
    Another, the most common case, regards not number, but distance and size. When I see a jetliner approaching to the airport, it seems at first small because it is very distant: the sensory content, that is, the sensory image is small. But I may insist in saying that what I see – the content of observation – is a big object that appears small because it is distant. The observational content can be said to be big, though it does differ from the sensory content – and the reason for this belongs to my physicalist interpretation of it. Now, after the jetliner lands, the sensory content or image is much bigger. I can even say, by implicit convention, that now I am seeing the jet in its real size; and it is big when compared with smaller aircrafts and other artefacts of metal. Now the visual image, the sensory content matches in size the observational content. We have what is conventionally seen as the standard perspective for the comparative measure of size in the case in question.
   Finally, we can get a paraphrase of the two different interpretations of our perceptual contents by saying that these sensory contents are made by the satisfaction of criteria demanded for the application of the verificational rule that constitutes the perceptual thought, for example ‘There is a jet approaching to land’. If we apply the verificational rule only imaginatively (that is if we consider the possible satisfaction of a sufficient number of its derived criterial configurations) we have a merely psychological perceptual content; on the other hand, when we effectively apply the verificational rule constitutive of the perceptual thought, when a certain number of its criterial configurations is sufficiently satisfied, then we may say that we have also a physical content of perception that – even if only perspectivally achieved – allows us to affirm that we are seeing the jet approaching for landing, that this process or fact really exists as part of the external world.
   Applying all this to our view of truth, when we wish to confirm a perceptual hypothesis ?p, the given perceptual contents !q are interpreted in the physicalist perspective (B), as observational contents. They are postulated – within a supposed linguistic practice – as evidential contents of observational experiences or truth-makers. Since their thought expressed by !q is a rule of verification, and the operator ! says that this rule is effectively applied, we know that the thought is a fact, that the fact is real, it exists in the external world. However, when the linguistic practice is rejected because of some unexpected contextual element, as in the case of the rubber dolphin considered in our example, then the same content is able to be interpreted only in the (A) sense, as a mere visual image suggestive of something that does not really exists. This explains why the verificational rule corresponding to our fact in the world may be applied but not effectively applied because this application was refuted by a contextual information that makes the application not effective, the fact not real, not existent.
   Another problem that could be rise is that of statements about the perceptual world that are not directly verified by perception, for example, the case of Ms. Rose criminal act. One could object that the statement !p = ‘Tried Ms. Rose to poison reverend David?’ is verified by the fact expressed by !q, that Ms. Rose indubitably tried to poison reverend David. But !q is in the case no perceptual statement, since it is inferred from statements r, s, t. But if it expresses a fact, it seems that it cannot be in the world, but in our minds, as the result of our reasoning. The answer is in my view that when we conceive !q, we conceive it with the same kind of duplicity of (A) and (B). It can be conceived in a psychological way, as a sensory content that one could have (I can imagine Mary trying to poison Mr. David), or (B) in a physicalist way, as an unperceived perceptual content independent of ourselves, that exists because it satisfies the criteria of reality. In the last case, we are considering the content of q not properly as a thought but as a fact in the world, what means the same as a rule of verification that is effectively applicable. And we know this because we have indirectly verified ?p.
   The next important question concerns an investigation of the general criteria that allow us to distinguish between the psychological and the physicalist interpretations of the contents of perception. We spoke about the effective applicability of the rule of verification. But what does it imply? I think that this view is intermingled with other criteria of external reality that were considered from philosophers like Locke, Berkeley, Hume, Kant, and several others. I think that these criteria together, when applied to a perceptual content, are sufficiently strong to warrant that this content can be seen as belonging to the external, physical world.

Criteria for the attribution of external reality to perceptual content
As we saw, when we discussed Berkeley’s and Mill’s phenomenalism, the sensations, even if they are only possible ones, are psychological, what leads us to the pitfalls of idealism regarding what is given to us in the perception. The only way to prevent this is to find criteria for an interpretation of what is given to the sensory experience (the contents of perception from the perspective (B)) that enables us to consider it as belonging to the external world, as s-properties (tropes). Mill, though confusing the object (matter) with its existence (the permanent possibilities of sensations), instead of considering it what as kind of content of perception whose experience is (while it exists) permanently possible, wrote that these possibilities (as matter) are objective, that is, since they belong to an intersubjectively accessible public world, while the sensations in themselves remain inevitably subjective. Mill also noted that his possibilities of sensation would follow regularities of nature, like the causal laws of physics, and that they are independent of our will, which are typical of matter.
   We can do better than Mill. We know that the permanent possibilities of sensations can be approximated to existence, but not with matter, because different matters (that is, different substances, material things) differs one another in different ways, while existence is always the same, namely, the property of matter (I would say, of material things) of existing. Moreover, we proposed that the contents of perception can be not only subjectively interpreted – as psychological contents – but also objectively interpreted – as s-properties or tropes. Indeed, what Mill noted, the permanent possibility of sensations, the objectivity (intersubjectivity), the following of regularities, the independency of will, are all criteria for the existence or reality of external things. This means that these properties can be taken as criteria for the interpretation of the contents of sensation as belonging to the external world, that is, as s-properties our tropes: these properties and their sets (i) should be permanently accessible under adequate conditions (during some time, called the time of their existence), (ii) should be intersubjectively accessible, (iii) should follow follow regularities (primarily physical laws), (iv) should be independent of our will. These are indeed criteria of external reality that have been considered by several traditional philosophers as Locke, Berkeley, Hume, Kant, Frege and Moore. To this we could add (v) Berkeley’s and Hume’s suggestion that we could call an idea external when it enters with the greatest force in our soul (that is, which is given to our percepts in its maximal intensity). The analytic philosopher G.E. Moore has attempted to summarize these criteria of reality in a paper in the following passage:

The real is something independent of the mind that is verifiable by others, continuously connected with other things, and in this way has certain causes, effects and accompaniments (I would say that it ‘displays regularities’) with the highest degree of reality.[18]

    It is true that when considered in isolation these criteria do not warrant that contents of perception (seeing under the perspective (B)) are externally real. For example: a sensation can have the most intense degree of intensity and be hallucinatory, as in the alcoholic psychosis. And a very realist dream can be tediously conformed with the expected regularities of our physical and social reality. Moreover, a dream is usually independent of our will, though not always (as the lucid dreams). An even interpersonal agreement about states of affairs can occur, in the case of a collective hallucination. And external occurrences can be directly dependent of our will (in the case we have a brain-reader associated to our motor-cortex).
   However, this is not the point. There is a way in which these conditions can be transformed in a definitional criterion and in a sufficient condition for the ascription of reality in the most important sense of the word, which I call inherent. It is when we demand that these conditions are given all together for enough time. Thus, suppose that under normal circumstances I see my personal computer in front of me. I know that this complex group of contents of sensation is presented to me as a complex group of mental images and sensations. But I also know that I can consider  that this content is given to me as something external, since it is given in the most intense degree, since it is co-sensorially given (I can see and touch the personal computer), since I am (because of similar past experiences) sure that other persons would agree that it is here in front of me (if they were here to see it), and since the device follows the expected physical regularities, and since after a while it is clear that these sensations are permanently possible. All of this warrants to me that the personal computer I am seen is not an imaginary combination of contents of sensation, but a content of sensation that can be considered as a belonging to the real world around me. We can summarize contents of sensation that can be seen as externally real as those that satisfy the following criteria:

    DEFINITORY CRITERION OF (INHERENT) EXTERNAL REALITY:
A content of experience can be seen as an externally real perceptual content (in the sense (B))
Iff
(i) it is permanently presentable to potentially intersubjective experience (they are owners of warranted and continuous possibility of sensations, using Mill’s words).
(ii) it is given to our senses in the most intense degree,
(iii) it is (normally) co-sensorially given,
(iv) it is (usually) independent of our will,
(v) we are sure that it is potentially subject of intersubjective experience and agreement,

   On the other hand, purely psychological contents of perceptual thought, as much of imaginary sensory contents (as the hallucinatory ones), lack these properties in part or completely.
   In other words, considering our rules of verification, our thoughts, we can say that a perceptual thought can be considered in two ways: (A) as a rule of verification that we know that we are able to apply only in the imagination, and in this way has a psychological existence; on the other hand, a perceptual thought can be considered as (B) a rule of verification that is effectively applicable, since it was applied, since enough of the multiple criteria that it can generate is satisfied. Moreover, there are criteria for the effective application of this perceptual rule of verification: It must (i) be applicable in a manner in which its criteria are satisfied in the most intense degree, (ii) it must be (normally) co-sensorially applicable, (iii) it must be (usually) applicable independent of our will, (v) we are sure that it is potentially applicable by other subjects too, leading to intersubjective agreement.
   I am not denying that in the cases of artificial reality or skeptical hypotheses the definitional criterion considered above can be in part or even totally mimetized. But curiously enough, when it is totally mimetized, as in the case of a skeptical hypothesis (ex: someone discovers that he is a brain in a vat or that we are living in a machine of virtual reality or that the world is a dream) the (inherent, that is, typical) reality of what is experientially given in the skeptical hypothesis is not denied. These contents remain very real indeed, though we deny to then an ultimate reality. They are, we could say, inherently real, even if they are not adherently real, since they do not belong comparatively to the what is supposed as an ultimate reality, but are a by-product of it. Consequently, though inherently real, they are non-real in the adherent sense, since they are the product of a world that relatively to them is not only inherently, but also adherently real. However, since the inherent sense of reality is our usual one, and we are not dealing directly with the problem of skepticism, this point is of a few interest to our present concerns. [19]
   Finally, we should remember, perceptual contents understood in the sense (b) are s-properties (or tropes) given to us always perspectivally. And when we join them to form an object or a fact in the world, what we have are not only complexes of s-properties, but complexes of complexes of s-properties, that is, hypercomplexes of s-properties. And the whole world can be understood as a hypercomplex of hypercomplexes of… complexes of s-properties. But it is better to stop this discussion here, since it is also not the aim of this book the development a fully argued ontology of s-properties or tropes (see my views about this issue in Appendix IV).

Are we falling into a myth of the given?
One could ask if we are falling into Wilfrid Sellars famous myth of the given regarding what we call the content of experience. The argument against the myth of the given can take the following form:

(1)  our beliefs regarding facts in the external world are only justified by the way they are given in the sense-experience;
(2)  sense experience isn’t part of the external world;
(3)  sense experience isn’t part of the products of our conceptual cognition like thoughts and beliefs;
(4)  from (1 and 2) classical empiricists conclude that our knowledge of the world is inferred from sense experience;
(5)  since inferences derive knowledge from knowledge, sense-experience must be itself a form of knowledge.

   This is the so-called the doctrine of the given. However, Sellars objects that this doctrine is inconsistent, for (3) is incompatible with (5): since sense experience isn’t part of the products of our conceptual cognition, sense experience cannot itself be a form of knowledge. Consequently, the attempt to ground our knowledge in what is given in the sense experience alone, defended by the classical empiricism, is a myth.[20]
   A first point to be noted is that when the content of experience that we are considering as the truth-maker (fact) is understood as an observational or perceptual content located outside of the subject. So, to our case the condition (2) does not apply. Moreover, this content, as any other, isn’t considered alone; it is always considered in the dependence of the context of a linguistic practice, what makes it totally different from ‘the given’ targeted by Sellars.
   Finally, in my view even when we consider the sensory-perceptual experience psychologically only as a sensory content, Sellar’s argument also does not apply. The reason is that as far as the elements constituting sensory contents (supposedly now ‘the given’) are connected or unified, they are already of a conceptual nature, even if not of a linguistic-conceptual nature, since for the last case we would in principle be able to express this unity by means of a concept-word. Consequently (3) does not need to apply to pure sensory-contents as necessarily as Sellars believes. It is possible to suggest that sensory experience may be itself conceptual, though non-linguistic, and in this way also a form of knowledge, so that we can easily derive linguistically articulated knowledge from it. That this conclusion is true is made clear by the knowledge that we subscribe to animals that lack any language. Animals that lack a language must be able, for example, to recognize a prey or an enemy visually, and by doing this they must unify their visual sensory experience in the form of non-linguistic concepts. Though I am not defending any form of classical doctrine of the given, I cannot agree that Sellar’s argument alone is decisive against any but a narrower understanding of ‘the given’.

Are we falling into externalism or idealism?
If a perceptual content is something that is outside of us, but can be considered as a rule of verification that is effectively applicable, and if a rule of application is a thought, then the fact, the truth-maker, is an effectively applicable (externally existent) thought. One could object that this corresponds to the acceptance of externalism.
   However, in doing so one forgets that when we speak about what is true or false we are speaking not about the fact in the world or the effectively applicable thought expressed by !o, but of the internal result of the correspondence, of what is made true, namely, of the thought expressed by !p that we conclude to be effectively applicable because it is equal to the thought that verifies it as being effectively applicable. And this thought is internal.
   Another objection would be that even if we are not being externalists in the usual sense of the word, we are embracing phenomenalism. With this I would agree, though I think that this phenomealism must be very well qualified. At first, it is a kind of phenomenalism that is compatible with direct realism: the things that satisfy the criteria of reality are all real and directly given, even if they are the given criteria of rules of verification that are effectively applicable. This is so because these criteria of a rule of verification that is only effectively applicable isn’t of a rule that does need to be effectively applied by any thinking being: indeed, many rules of verification – that are effectively applicable – that constitute real existing facts – have never been thought of or being effectively applied by any human being. Thus, our kind of phenomenalism, when well considered, does not commit us with any kind of idealism, since the external world still satisfies all criteria of reality or existence or objectivity, and remains independent of our minds.
   Finally, our kind of phenomenalism does not commit us with ontological realism about thoughts, since the f-thoughts that have truth-value are for us only those expressed by !p and not the objective perceptual contents expressed by !o, which originate truth-values, need to satisfy the criteria of inherent reality, and constitute, through their effective applicability, the existing external world.

Correspondence, verification, and intentionality (Husserl)
Now we can come back to our initial problem. We have two seemingly incongruent theses. The first is the thesis that truth, in analogy with existence, which is the effective applicability of a conceptual rule, should be the effective applicability of a rule of verification (an f-thought), being in this way assimilated in the concept of the existence, not of a property, but of the fact conceived when we consider the rule of verification. The second is that truth is correspondence, that is, the identity of content between ?p and !q, as we have shown by means of many examples. However, are these not very different and maybe incompatible views?
   I think that we can bring some light to this problem reconsidering some of Edmund Husserl’s views on truth in his Logical Investigations.[21] I believe that he has shown the right path, even if in tentative and often obscure ways. As we saw, Frege spoke on senses as meanings and thoughts, understanding them as abstract entities. Wittgenstein has suggested instead, according to our interpretation, something that leads us to the admission that the meaning is given by cognitive-semantic rules or combinations of rules considered in a particularist way, as something that can be applied either effectively (to the real world) or at least imaginatively (as a possibility), what we are able to do when we can consider a thought without knowing its truth-value. Husserl, before Wittgenstein, has instead spoken of intentional acts as instantiating meanings, which should be for him, as for Frege and other German philosophers of the time, abstract entities. My take is that Frege, Husserl and Wittgenstein were all dealing with the very same thing, though from very different points of view and assumptions. Fregean senses, as we saw, if they are something, they must be cognitive-semantic rules or combinations of such rules. But the same applies to Husserl’s intentional acts: they are – in accordance with our view of the semantic as always psychologically instantiated – cognitive instantiations of semantic rules or combinations of rules, which can be expressed respectively in a cognitivist (psychological, as Husserl unwilling does) or in a semanticist (linguistic) fashion.
   Having in mind this hypothesis, I will first present the essentials of Husserl’s theory of intentionality and his correspondence theory of truth. Then I will translate his main ideas in our own language. And finally I will show how the insights we may get through these considerations can bring us to a clearer understanding of the relationship between semantic verificationism and the correspondence theory of truth.
   According to Husserl’s view, the meaning (sense) of a linguistic expression is an ideal, an abstract (platonic) object, as it was for Frege and other German philosophers of the 19th century. But the meaning of an expression can be instantiated through two fundamental kinds of intentional acts: (a) In a meaning-conferring intentional act (a bedeutungsverleihend Akt or Bedeutungsintention), which abstracts of its application to the reality or (in the case of a sentence) of its truth-value (for example, I think about my sunglass, I think that my sunglass is in the drawer); (b) in a meaning-fulfillend intentional act (a bedeutungserfühlend Akt) related to the same expression or sentence (for example, I see my sunglass in the drawer after I opened it). In this last case the object of the act is not only intended, but also given to us ‘in person’, even if always in perspectival ways by means of distinct intuitions. Finally, there is a third act, an act of synthesis, in which we make ourselves aware that the object intended in the meaning-giving intentional act is the same as the object given in the meaning-fulfilling intentional act. For Husserl, through this last act we achieve the awareness of the truth and in this way also knowledge.[22] The truth, according to him, is correspondence, because it is the sameness of the object intended by the meaning-conferring act with the object intended by the meaning-fulfilling act. As he writes, truth is ‘the complete agreement of what is intended with what is given as such.’[23] Admitting that there can be an undetermined diversity of perspectival acts of fulfilment adding one another in order to warrant our knowledge of the object, giving to the experience its evidential value, he also writes:

When a presentative intention finds its last fulfilment, the genuine adequatio rei et intellectus is realized. The object is really presented as intentioned. So is the idea of all signitive fulfilment. The intellect is the intention of thought, the intention of meaning. The adequation is realized when the intentioned object in the strict sense is given to us as it is thought.[24]

   This correspondence as the identity between the objects of the two intentions is what seems to me Husserl’s chief insight on the nature of truth.[25]
   Now, we can read the meaning-conferring and the meaning-fulfilling intentional acts as two cognitive-semantic rules. The meaning-fulfilling intentional act is a cognitive-rule that we are able to consider, that is, that we see that it is able to be satisfied or applied, that we can imaginatively apply it to a greater or less extent. And in the case in which it is expressed by an assertive sentence this cognitive-rule is a verification rule that can be true or false, effectively applicable or not. On the other hand, the meaning-fulfilling intentional act is a cognitive-rule in its effective satisfaction or application. In the case in which we can express the effectively applied cognitive-rule in the form of an assertive sentence, we are considering it as a verificational rule that is effectively applied and insofar has the property of being true.
   Considering the thought-content as a verification rule, then it seems clear that ?p expresses a verification rule (or part of it) that is only considered or only imaginatively applied, applied only in our minds, and that !q, which gives the evidence, expresses another verificational rule, which is effectively applied to the reality, that is, to what satisfies our criteria of inherent reality. If these rules are exactly similar, if p = q, and they are applied in their respective fields, the first rule, the thought that p, is called true, otherwise not. And the same we can say of the factual content that !q expresses: if q = p then the factual content exist, the fact predicted by ?p really exist in the actual world.
   Now, even if we agree that the two verification rules expressed by p and q must have exact similarity in order to warrant correspondence, what has this to do with the effective application of the verification rule? Wouldn’t be more sensible to understand the expression ‘verification rule’ as describing the whole process of verification? For example, the process described in the following example concerning the poor husband of Ms. Rose:

!r, !r > ?p, {!r & !s & !t & !u} >>> !q, p = q/p

The only answer I can find is that here we have here two senses of ‘rule of verification’ and that we should not confuse them. In the first sense the rule of verification can be identified with the meaning of a proposition, but not in the second:

(a)      In the first sense, the verification rule is considered separately from the correspondence procedure. This is the rule effectively applied when we see or conclude that !q, which can be the same whose application was only imaginatively conceived in ?p. This is also the rule expressed by !q, which is exactly similar, though considered effectively applicable to the fact given in the world. And this is also the case of the applied verification rules !r, !s, !t and !u in the given example. These are the rules of verification identified with the f-thought or sense/meaning of the sentence.
(b)       In the second sense, the rule of verification is the whole procedure of verification summarized and exemplified in the above formula and in all the others. It is important because, though it cannot be identified with the f-thought or sense of a sentence, this is the only sense in which verification can be really equated with correspondence. When we speak about the sense of a statement – of its thought – we are speaking about a verification rule p, for example, whose application we are able to think, even if only partially; but when we are speaking about the whole procedure of verification, we are speaking about the process of achieving or not achieving the correspondence relation, namely, the match or mismatch between the numerically different rules of verification or f-thoughts. In the foregoing case, for example, what we have is a match of contents between the only considered or imaginatively applied verification rule ?p and the effectively applied verification rule !q. And this last rule is postulated as effectively applied, in the case as the inductive result of the effective application of the conjunction of the different verification rules !r & !s & !t & !u, each of them having been already the submitted to a similar process.

   To make the point clearer, I give a simpler example. I get my car in order to go to the university, since I need to give a class. As I enter in the free-way I see that the amount of cars on the road is unusually small. I begin to ask if it is a holyday. This is my ?p. I do not thing about the many ways I know to verify this hypothesis; but I know its implications. One of them is that I will not have any class today; another is that I am losing my time. These inferences are more or less related to the meaning of the hypothesis ?p, though they do not build its kern. Since I am without a mobile phone, some minutes later I am in the university only to verify that it is closed. I ask the policeman, who answers that today is a state holyday. My awareness that in fact it is holyday is the result of the effective application of the rule of verification by a cumulative satisfaction of criteria, the last of them letting no doubt. This result is !q. Since p = q, p is true.
   It is worth to note that first, both p and q express the same rule of verification. Although differently (and partially) considered and applied or satisfied, both express the same meaning (even if differently and partially accessed), the same grounding thought.[26] Second, I can consider that I verify that today is holyday, considering the whole process described in the form ‘?p, !q, p = q/├p’, and I can call it a verification. But in this sense verification cannot be identified with the thought or sense/meaning of a proposition.  
   Now, comparing the view I am suggesting with Husserl’s theory of truth, we see that we are able to overcome the two main drawbacks seen by his critics. The first and more serious is that working only with intentional-fenomenal material, Husserl is unable to explain the access to the object ‘in person’, to the object in itself, since this would demand him to go beyond the phenomenon.[27]
   Our understanding of correspondence allows us to escape from these limitations. In our words the thought ?p, which is for us an only considered thought or a rule of verification in its conceived application, can be approximated with what Husserl calls a meaning-conferring intention. A thought-content like !o, which is for us another rule of verification that may be expect to be similar in content with ?p, is the effectively applied rule of verification, which is what Husserl calls the meaning-fulfilling intentional act. And the awareness of the identity (or the congruence) ‘p = o’, which brings us to the conclusion ├p (that p is true), can be approximated with Husserl’s conclusion that we achieve truth when the objects of the two acts are the same.
   However, we do not need to follow Husserl here and we do not need to expose his Platonism. As you remember, according to our analysis the existence is the effective applicability of a conceptual rule, while the object of its application should be only conceived as the sum of the conditions to which the conceptual rule can be applied, and its having existence is its potentiality of having the conceptual rule applied to it. The rule of verification demands for its application the satisfaction of criterial configurations through which the real fact, the fact in the world, presents itself to us. These criterial configurations, on the other hand, when they are perceptual, are manifestations of this empirical fact, and can be interpreted not only as a (A) configurations of sense-data, but also as (B) real parts of empirical things (as tropes and configurations of tropes), as far as they satisfy the (inherent) criteria of external reality (the possibility of being interpersonally accessed, the maximal intensity of sensation, the independence of will, the following of natural regularities…). These configurations are at least parts of the ‘object in person’, but although being perceptual contents, they can be seen as externally real and completely independent of the subject of perception. And they exist in the independence of this subject because the existence of the fact is the effective applicability of the verification rule, the truth of the thought corresponding to it, which is the effective applicability of the verification rule and also the correspondence in the sense of similarity between the considered, only imaginatively applicable verification rule, and the effectively applicable verification rule, which we consider as such because of acts of verification.
   The second objection against Husserl’s view is that the object is never given to us in its entirety. Since what we experience are always of parts of the object, it cannot be really given to us ‘in person’. Husserl saw this problem and suggested that the object could still be seen as a pure or empty X of ideal nature.[28]
   Also under the view we have proposed it is true that neither the object nor the fact are perceptually given to us in their entirety, with the consequence that we cannot be absolutely sure that what is being given to our experience is the real object or fact. However, we can infer that the object is given with enough probability to assume as warranted the evidence posed by !o and, consequently, the truth of !p under the circumstances of an adequate linguistic practice and the assumption that other things remains the same. We can infer that we have seen a dolphin and not only the back of a dolphin moving on the water, and we can postulate what is given as an evidence, insofar as we can assume the circumstances of the language game we are playing as undefeated.
   Finally, it is worth to note that the most important concept used in this book was that of effective applicability of a cognitive rule. Not only because it is a key for the understanding of existence and truth as correspondence, but also because it allows us to give a more hopeful solution to the problem of perception.







[1] I searched the meanings of the word ‘truth’ word in different dictionaries in English, German, Portuguese and French, so I am restricted to some few Indo-European languages. But at least in these languages the similarity of uses is remarkable.
[2] I take all these examples from dictionaries.
[3]  One important point of Wittgenstein’s the Tractatus Logico-Philosophicus is that he saw that we cannot explain representation without the resource of some kind of possible structural isomorphism between thought and fact.
[4]  Ludwig Wittgenstein: Tractatus Logico-Philosophicus,  2.2 f.
[5] We can make things true, for example, by acting in the world in order to change it, as constructivist philosophers since Vico have noted, but it is the final fact in the world, as the product of the human work, that is the object of the correspondence and has to do with truth as the truth-maker, and not the opposite.
[6] We remember here Alfred Tarski’s disquotational formula, according to which ‘“p” is true in L ≡ p’. Tarki’s formula hasn’t overcome the philosophical (epistemological and ontological) problems concerning correspondence, since it would say that in the case in which Fa, F is satisfied by the object referred by a, but does why it is satisfied by a certain object and not by any other, since it does not say under what conditions the referred object satisfies F. However, I think that Tarski’s approach has properly emphasized the metalinguistic character of the truth-assignments. (See Alfred Tarsky: ‘The Semantic Conception of Truth’, Philosophy and Phenomenological Research, 4, 1944, 341-375).
[7] This point will be developed later in my answer of the objection of the linguistic circle.
[8]  Moritz Schlick, ‘Wahrheit als Korrespondenz nach der modernen Logik’ (1910), in Philosophische Logik (Frankfurt: Suhrkamp 1996).
[9] Edmund Husserl: Logische Untersuchungen (Tübingen: Max Niemayer Verlag, 1980), vol. II/2, VI.
[10] See Robert Sokolowski: Russellian Meditations (Evanston: Northwestern Univerisity Press, 1074), chap. 9.

[11] See Robert Sokolowsky, Russselian Meditations, ibid., chap. 9.
[12] I take this distinction from Husserl’s phenomenology: it is the distinction between ‘truth of correctness’ (Wahrheit als Richtigkeit) and ‘truth of disclosure’ (Wahrheit als Entdeckheit). See Robert Sokolowski, Introduction to Phenomenology (Cambridge: Cambridge University Press, 2000), p. 158.

[13] Ludwig Wittgenstein: Philosophische Untersuchugen, part I, sec. 244.
[14]  I take this example from P. K. Moser, Dwayne H. Mulder & J. D. Trout, The Theory of Knowledge (New York: Oxford University Press, 1997), chap. 4. They also present cases of ethical imperatives like ‘One should help the life of someone in danger, as far as this does not endangers his own life’. But imperatives are not the kind of thing that is usually called true; it does not require correspondence with a fact, but normative correction – correspondence with the general norm, at most.
[15] Consistence isn’t sufficient for coherence, since two completely unrelated statements like ‘2 + 2 = 4’ and ‘Red is a colour’ can be consistent without that one increases the coherence of the other.
[16] “Truth”, in A. J. Ayer: The Concept of Person and Other Essays (London: Macmillan Press, 1963) p. 186.
[17] Russell defended neutral monism in his book The Analysis of Mind (London: George Allen & Unwin, 1921) and in some other texts, though he had eventually abandoned this view.
[18] G. E. Moore, ‘The Meaning of Real’, in his Some Main Problems of Philosophy (London: George Allen & Unwin, 1953).
[19]  I answered the sceptical problem distinguishing between inherent and adherent senses of reality in the chapter 6 of my book Lines of Thought: Rethinking Philosophical Assumptions (Cambridge Scholars Publishing, 2014).
[20] Wilfrid Sellars: Empiricism and the Philosophy of Mind, Minnesota Studies in the Philosophy of Science, vol. 1. (eds.) H. Feigel, M. Scriven (Minneapolis MN: University of Minnesota Press, 1956), pp. 253-329, sec. 3, 12, 18, 19, 30, 32. In my understanding, however, though the component unities of a sense-data cannot be in themselves conceptually grasped, they can be conceptually grasped as the elements integrated with the whole unity of what is being perceived.
[21] Edmund Husserl: Logische Unversuchungen, vol. II, VI.
[22]  According to Husserl truth is the identity between what is intended (gemeint) and what is given, while knowledge is the identity between what is meant (gemeint) and what is given.
[23] Edmund Husserl: Logische Untersuchungen, VI, sec. 38.
[24] Edmund Husserl: Logische Untersuchungen, sec. 37.
[25] In fact there are four different concepts of truth in Husserl: (1) ‘full agreement between what is meant and what is given as such’, (2) ‘the idea which belong to the act form’ (3) ‘the ideal fulfilling of an intention’ (4) ‘the rightness of the epistemic essence of the intention in specie’. They are not only terribly obscure, but also committed with his Platonist ontology, which I am trying to avoid. See Logische Untersuchungen II, VI, sec. 39.
[26]  See our analysis of fact-identity in chapter 3, in the section entitled ‘The reference of the sentence as a fact’.
[27] As Günter Patzig has noted, here ‘the daring bridge called evidence intended to connect the judgment with the fact had the drawback, rather unfortunate in a bridge, that it ended on the same side of the river from which it began’, in ‘Husserl on Truth and Evidence’, in J. N. Mohanty (ed.): Readings on E. Husserl’s Logical Investigations (De Hague: Nijhoff, 1977), p. 194.
[28] As Peter Simons notes, ‘In particular, each noema has a kernel or nucleus which consists of three elements: a substratum, a set of qualitative moments, and modes of fulfilment of these qualities. What he calls a pure of empty X is the subject of predicates that are intended in the nucleus and which are more or less intuitively fulfilled. (…) this X is not a further concrete constituent in the noema; it is an abstract form occurring in it (Ideas 131).’ See ‘Meaning and Language’, in The Cambridge Companion to Husserl , ed. B. Smith & D. W. Smith (Cambridge: Cambridge University Press, 1995), p. 127.