Truths ancient and modern

The paper presents a comparison of the theories of truth, and the solutions of the liar paradox, proposed by Thomas Bradwardine (c. 1290-1349), Jean Buridan (c. 1295-1358), and Alfred Tarski (1901-1983).

The role of consistency in empirical science

Any inconsistent theory whose underlying logic is classical encompasses all the sentences of its own language. As it denies everything it asserts, it is useless for explaining or predicting anything. Nevertheless, paraconsistent logic has shown that it is possible to live with contradictions and still avoid the collapse of the theory. The main point of this paper is to show that even if it is formally possible to isolate the contradictions and to live with them, this cohabitation is neither desired by working scientists not desirable for the progress of science. Several cases from the recent history of physics and cosmology are analyzed.

Consistency from the perspective of an experimental systems approach to the sciences and their epistemic objects

It is generally accepted that the development of the modern sciences is rooted in experiment. Yet for a long time, experimentation did not occupy a prominent role, neither in philosophy nor in history of science. With the 'practical turn' in studying the sciences and their history, this has begun to change. This paper is concerned with systems and cultures of experimentation and the consistencies that are generated within such systems and cultures. The first part of the paper exposes the forms of historical and structural coherence that characterize the experimental exploration of epistemic objects. In the second part, a particular experimental culture in the life sciences is briefly described as an example. A survey will be given of what it means and what it takes to analyze biological functions in the test tube.

Formal semantics for propositional attitudes

Contemporary logic is confined to a few paradigmatic attitudes such as belief, knowledge, desire and intention. My purpose is to present a general model-theoretical semantics of propositional attitudes of any cognitive or volitive mode. In my view, one can recursively define the set of all psychological modes of attitudes. As Descartes anticipated, the two primitive modes are those of belief and desire. Complex modes are obtained by adding to primitive modes special cognitive and volitive ways or special propositional content or preparatory conditions. According to standard logic of attitudes (Hintikka), human agents are either perfectly rational or totally irrational. I will proceed to a finer analysis of propositional attitudes that accounts for our imperfect but minimal rationality. For that purpose I will use a non standard predicative logic according to which propositions with the same truth conditions can have different cognitive values and I will explicate subjective in addition to objective possibilities. Next I will enumerate valid laws of my general logic of propositional attitudes. At the end I will state principles according to which minimally rational agents dynamically revise attitudes of any mode.

Matrix- based logic for avoiding paradoxes and its paraconsistent alternative

The present article shows that there are consistent and decidable many- valued systems of propositional logic which satisfy two or all the three criteria for non- trivial inconsistent theories by da Costa (1974). The weaker one of these paraconsistent system is also able to avoid a series of paradoxes which come up when classical logic is applied to empirical sciences. These paraconsistent systems are based on a 6- valued system of propositional logic for avoiding difficulties in several domains of empirical science (Weingartner (2009)).

Varieties of the generality constraint

Since its introduction by Evans (1982), the generality constraint (GC) has been invoked by various philosophers for different purposes. Our purpose here is, first, to clarify what precisely the GC states by way of an interpretive framework, the GC Schema, and second, to demonstrate in terms of this framework some problems that arise if one invokes the GC (or systematicity) without clearly specifying an appropriate interpretation. By utilizing the GC Schema these sorts of problems can be avoided, and we thus propose it as a tool to facilitate argumentation that appeals to the GC.

The transcendence of time in the epistemology of observation from a phenomenological standpoint

In this article I deal with time as a notion of epistemological content associated though with the notion of a subjective consciousness co-constitutive of physical reality. In this phenomenologically grounded approach I attempt to establish a 'metaphysical' aspect of time, within a strictly epistemological context, in the sense of an underlying absolute subjectivity which is non-objectifiable within objective temporality and thus non-susceptible of any ontological designation. My arguments stem, on the one hand, from a version of quantum-mechanical theory (History Projection Operator theory, HPO theory) in view of its formal treatment of two different aspects of time within a quantum context. The discrete, partial-ordering properties (the notions of before and after) and the dynamical-parameter properties reflected in the wave equations of motion. On the other hand, to strengthen my arguments for a transcendental factor of temporality, I attempt an interpretation of some relevant conclusions in the work of J. Eccles ([5]) and of certain results of experimental research of S. Deahaene et al. ([2]) and others.

Universales estructurales

The work presents the concept of a structural universal and the criticisms that have been leveled against it. A structural universal is a property had by an individual due to the nature of its proper parts and due to the relations obtaining between those parts. Mellor has argued that there is no reason to accept such universal in addition to the basic universals that compose them. David Lewis has argued -on the other hand- that it has not been satisfactorily explained how universals are composed by other universals. The composition by which a structural universal is given cannot be a set-theoretical construction or a mereological sum. Several proposals to explain the nature of structural universals are discussed. Finally it is argued that a structural universal should be understood as a complexion of higher-order universals.

Apercepção subjetiva e conhecimento objetivo: uma leitura sobre o lugar do 18 na estratégia da Dedução B da Crítica da Razão Pura

Neste artigo, procuro avaliar o sentido para o projeto dedutivo da Crítica da Razão Pura da distinção, apresentada no 18 dessa obra, entre unidade objetiva e unidade subjetiva da apercepção. Primeiramente, apresento o objetivo geral e os passos fundamentais da dedução transcendental das categorias do entendimento. Em seguida, identifico o esboço de uma estratégia argumentativa, inaugurada no 18 da Dedução, fundada na compreensão da unidade subjetiva da apercepção como um juízo de percepção acerca de "objetos subjetivos". Finalmente, defendo que uma dedução assim construída não é uma prova consistente da possibilidade do conhecimento objetivo, na medida em que pretende se furtar à tarefa de demonstrar que as categorias do entendimento são condições da possibilidade da nossa percepção pré-judicativa de objetos sensivelmente intuídos.

É incoerente a concepção de Searle sobre a consciência?

O artigo investiga a frequente alegação na literatura filosófica de que a concepção de Searle sobre a redução da consciência é incoerente. Após um exame das teses básicas de sua teoria da mente (seção 2), é discutida sua posição a respeito da identidade entre a consciência e a atividade cerebral (seção 3). Da adesão de Searle a uma tese da identidade de ocorrências deve-se concluir que não há contradição entre esta tese e a irredutibilidade ontológica que ele defende. Porém, é possível deduzir de sua teoria asserções que contradizem esta mesma teoria (seção 4), uma vez que essa irredutibilidade resulta em um dualismo de propriedades (seção 5).

Philosophia prima como repraesentatio na filosofia natural de Hobbes: exame de fundamentos metafísico-cognitivos como complementos teóricos de seu materialismo mecanicista

O ponto de partida da Philosophia prima de Hobbes tem como referência a Física e a Metafísica de Aristóteles. O desenvolvimento posterior de sua Philosophia prima, porém, põe em marcha uma crítica da metafísica aristotélica que conduzirá a um remanejamentoteórico de uma série de princípios e conceitos herdados da tradição. Considerada em seu conjunto, a filosofia primeira hobbesiana é constituída por uma definição ampla, isto é, a metafísica definida como ciência do ente enquanto ente (ao invés da clássica definição de ciência do ser enquanto ser), sobre a qual duas definições strictu sensu são erigidas: a metafísica como física geral - dizer o ente (ens) é dizer o corpo (corpus) - e a metafísica como representação. Este paper é um esforço no sentido de compreender essas e outras questões concernentes aos estudos hobbesianos sobre a forma como conhecemos o mundo, as coisas e nós mesmos.

Book review of Consciousness by Christopher Hill

Christopher S. Hill advances a theory of conscious experience that employs the idea of representation to unify and explain a wide range of subjective phenomena, including emotions and pain. The theory shows the relevance of philosophical thought in a multidisciplinary view of the mind.

Os seis requisitos das premissas da demonstração científica em aristóteles (Segundos Analíticos I2)

Discuto neste artigo os seis requisitos que Aristóteles propõe para as premissas das demonstrações científicas em Segundos Analíticos I 2, 71b20-33. Pretendo mostrar que os seis requisitos não respaldam a interpretação "axiomatizante". Ao contrário, os seis requisitos podem ser entendidos consistentemente de acordo com uma interpretação segundo a qual o traço mais fundamental da demonstração científica consiste na explicação pela causa apropriada.

A caracterização da lógica pela força assertórica em frege. Resposta a Marco Ruffino

Segundo a caracterização padrão da lógica nos escritos fregeanos, a palavra "verdadeiro" indica a essência da lógica, assim como a palavra "bom" indica a essência da ética e a palavra "belo" a essência da estética. Num escrito póstumo de 1915, porém, Frege afirma que é a força assertórica, e não a palavra "verdadeiro", que indica a essência da lógica. Prima facie, esta correção está em conflito com a crítica fregeana à concepção psicologista da lógica. Pois, segundo esta crítica, a lógica não é a ciência das leis "do ser tomado como verdadeiro", mas a ciência das leis "do ser verdadeiro", ao passo que a força assertórica expressa o ser tomado como verdadeiro. Em escritos anteriores, tentei resolver este conflito por uma reconstrução da concepção fregeana da verdade baseada na tese fregeana de que verdade é expressa na linguagem natural pela "forma da sentença assertórica". A meta do presente trabalho é defender esta interpretação contra as objeções recentemente feitas por Marco Ruffino.

The relation between the general maxim of causality and the principle of uniformity in hume's theory of knowledge

ABSTRACT When Hume, in the Treatise on Human Nature, began his examination of the relation of cause and effect, in particular, of the idea of necessary connection which is its essential constituent, he identified two preliminary questions that should guide his research: (1) For what reason we pronounce it necessary that every thing whose existence has a beginning should also have a cause and (2) Why we conclude that such particular causes must necessarily have such particular effects? (1.3.2, 14-15) Hume observes that our belief in these principles can result neither from an intuitive grasp of their truth nor from a reasoning that could establish them by demonstrative means. In particular, with respect to the first, Hume examines and rejects some arguments with which Locke, Hobbes and Clarke tried to demonstrate it, and suggests, by exclusion, that the belief that we place on it can only come from experience. Somewhat surprisingly, however, Hume does not proceed to show how that derivation of experience could be made, but proposes instead to move directly to an examination of the second principle, saying that, "perhaps, be found in the end, that the same answer will serve for both questions" (1.3.3, 9). Hume's answer to the second question is well known, but the first question is never answered in the rest of the Treatise, and it is even doubtful that it could be, which would explain why Hume has simply chosen to remove any mention of it when he recompiled his theses on causation in the Enquiry concerning Human Understanding. Given this situation, an interesting question that naturally arises is to investigate the relations of logical or conceptual implication between these two principles. Hume seems to have thought that an answer to (2) would also be sufficient to provide an answer to (1). Henry Allison, in his turn, argued (in Custom and Reason in Hume, p. 94-97) that the two questions are logically independent. My proposal here is to try to show that there is indeed a logical dependency between them, but the implication is, rather, from (1) to (2). If accepted, this result may be particularly interesting for an interpretation of the scope of the so-called "Kant's reply to Hume" in the Second Analogy of Experience, which is structured as a proof of the a priori character of (1), but whose implications for (2) remain controversial.