Ideal Reasoners don’t Believe in Zombies

The negative zombie argument concludes that physicalism is false from the premises that p ∧¬q is ideally negatively conceivable and that what is ideally negatively conceivable is possible, where p is the conjunction of the fundamental physical truths and laws and q is a phenomenal truth (Chalmers 2002; 2010). A sentence φ is ideally negatively conceivable iff φ is not ruled out a priori on ideal rational reflection. In this paper, I argue that the negative zombie argument is neither a priori nor conclusive. First, I argue that the premises of the argument are true only if there exists an adequate finite ideal reasoner R that believes ◊(p ∧ ¬q) on the basis of not believing p→q on a priori basis. Roughly, a finite reasoner is a reasoner with cognitive limitations (e.g. finite memory). I argue that R is finite only if R reasons nonmonotonically and only approach ideal reflection at the limit of a reasoning sequence. This would render the argument nonconclusive. Finally, I argue that, for some q, R does not believe ◊(p ∧ ¬q) on the basis of not believing p→q on a priori basis (e.g. for q =‘something is conscious’). This would render the choice of an adequate q dependent on empirical information (and the argument a posteriori). I conclude that the negative zombie argument (and, maybe, all zombie arguments) is neither a priori nor conclusive

Logical Omnipotence and Two notions of Implicit Belief

The most widespread models of rational reasoners (the model based on modal epistemic logic and the model based on probability theory) exhibit the problem of logical omniscience. The most common strategy for avoiding this problem is to interpret the models as describing the explicit beliefs of an ideal reasoner, but only the implicit beliefs of a real reasoner. I argue that this strategy faces serious normative issues. In this paper, I present the more fundamental problem of logical omnipotence, which highlights the normative content of the problem of logical omniscience. I introduce two developments of the notion of implicit belief (accessible and stable belief ) and use them in two versions of the most common strategy applied to the problem of logical omnipotence

Um Embrião não é um Indivíduo (An Embryo is not an Individual)

Um argumento recorrente contra a liberalização do aborto parte do pressuposto de que, desde o momento da fertilização, seres humanos são indivíduos (no sentido de serem algo que necessariamente ocorre em uma entidade apenas). Nesse artigo, argumento que esse não é um caso a partir da possibilidade de geminação monozigótica e do fato de identidades serem necessárias. Defendo as premissas do argumento e discuto as possíveis interpretações de sua conclusão. Argumento que a interpretação completa da conclusão desse argumento está em concordância com a conclusão de um argumento semelhante, que parte de noção de organismo. ENGLISH: A common pro-life argument assumes that humans are individuals (in the sense that they necessarily occur in one entity only) from the moment of fertilization. In this paper, argue that this is not the case because of the possibility of monozygotic twinning and the necessity of identities. I will defend the premises of the argument and discuss the possible interpretations of its conclusion. I argue that the correct interpretation of the conclusion of this argument is in agreement with the conclusion of a similar arguments from the notion of organism

Minimalismo e suas Mentiras Generalizadas (Minimalism's General Lies)

A teoria minimalista da verdade consiste em todas as instâncias do esquema 'φ é verdadeira sse φ' e na afirmação de que nossa aceitação (primitiva) dessas instâncias é suficiente para explicar nossas atitudes em relação a todas sentenças envolvendo ‘verdade’. Filósofos têm apontado que o minimalismo tem dificuldades em explicar nossas atitudes em relação a generalizações envolvendo ‘verdade’ bem como em lidar com instanciações contraditórias do esquema para sentenças paradoxais (ex. paradoxo do mentiroso). Proponentes do minimalismo apresentam soluções para esses problemas. Nesse artigo, argumento que essas soluções entram em conflito, analiso algumas estratégias para resolver esse conflito e concluo que o minimalismo não pode evitar conflitos desse tipo mantendo seu caráter minimalista. ENGLISH: The minimalist theory of truth consists in all the instances of the schema 'φ is true iff φ' and in the claim that our primitive acceptance of these instances explains our attitudes in relation to propositions involving truth. Philosophers point that minimalism has difficulties in explaining our attitudes in relation to generalizations involving truth and with the contradictory instances of the schema for paradoxal sentences (e.g. the liar). Minimalists present solutions to these problems. In this paper, I argue that these solutions conflict with each other. I analyze some strategies to resolve this conflict. I conclude that minimalism cannot avoid the conflict maintaining it minimalist character

Almost Ideal: Computational Epistemology and the Limits of Rationality for Finite Reasoners

The notion of an ideal reasoner has several uses in epistemology. Often, ideal reasoners are used as a parameter of (maximum) rationality for finite reasoners (e.g. humans). However, the notion of an ideal reasoner is normally construed in such a high degree of idealization (e.g. infinite/unbounded memory) that this use is unadvised. In this dissertation, I investigate the conditions under which an ideal reasoner may be used as a parameter of rationality for finite reasoners. In addition, I present and justify the research program of computational epistemology, which investigates the parameter of maximum rationality for finite reasoners using computer simulations

No Rationality Through Brute-Force

All reasoners described in the most widespread models of a rational reasoner exhibit logical omniscience, which is impossible for finite reasoners (real reasoners). The most common strategy for dealing with the problem of logical omniscience is to interpret the models using a notion of beliefs different from explicit beliefs. For example, the models could be interpreted as describing the beliefs that the reasoner would hold if the reasoner were able reason indefinitely (stable beliefs). Then the models would describe maximum rationality, which a finite reasoner can only approach in the limit of a reasoning sequence. This strategy has important consequences for epistemology. If a finite reasoner can only approach maximum rationality in the limit of a reasoning sequence, then the efficiency of reasoning is epistemically (and not only pragmatically) relevant. In this paper, I present an argument to this conclusion and discuss its consequences, as, for example, the vindication of the principle 'no rationality through brute-force'

How to (Blind)Spot the Truth: an investigation on actual epistemic value

This paper is about the alethic aspect of epistemic rationality. The most common approaches to this aspect are either normative (what a reasoner ought to/may believe?) or evaluative (how rational is a reasoner?), where the evaluative approaches are usually comparative (one reasoner is assessed compared to another). These approaches often present problems with blindspots. For example, ought a reasoner to believe a currently true blindspot? Is she permitted to? Consequently, these approaches often fail in describing a situation of alethic maximality, where a reasoner fulfills all the alethic norms and could be used as a standard of rationality (as they are, in fact, used in some of these approaches). I propose a function α, which accepts a set of beliefs as inputand returns a numeric alethic value. Then I use this function to define a notion of alethic maximality that is satisfiable by finite reasoners (reasoners with cognitive limitations) and does not present problems with blindspots. Function α may also be used in alethic norms and evaluation methods (comparative and non-comparative) that may be applied to finite reasoners and do not present problems with blindspots. A result of this investigation isthat the project of providing purely alethic norms is defective. The use of function α also sheds light on important epistemological issues, such as the lottery and the preface paradoxes, and the principles of clutter avoidance and reflection

Necessariamente, Provavelmente não sou um Zumbi (Necessarily, Probably I am not a Zombie)

O argumento zumbi negativo parte das premissas de que p ∧ ¬q é idealmente negativamente concebível, de que o que é idealmente negativamente concebível é possível e de que o fisicalismo é incompatível com a possibilidade de p ∧ ¬q para concluir que o fisicalismo é falso. No argumento, p é a conjunção das verdades e leis físicas fundamentais e q é uma verdade fenomenal qualquer. Uma sentença φ é idealmente negativamente concebível sse um raciocinador ideal não acredita que ¬φ em reflexão priori. Uma versão da tese da escrutabilidade pressuposta pelo argumento afirma que, para todo φ que sobrevém em p, o raciocinador ideal acredita que p → φ em reflexão a priori. Nesse artigo, argumento que, dado algumas interpretações relevantes da noção de probabilidade (pr(.)), o raciocinador ideal acredita verdadeiramente, para todo φ, que p → pr(φ) = x em reflexão a priori. Mas então, dependendo do valor de pr(q) e das correlações entre q e outras sentenças, o raciocinador ideal também acredita (provavelmente, verdadeiramente) que p → q em reflexão a priori. Então, para alguns qs relevantes, p ∧ ¬q não é idealmente negativamente concebível e o argumento zumbi tem uma premissa falsa. A escolha de um q adequado dependeria de informação empírica, o que faria o argumento zumbi não ser nem conclusivo, nem a priori. ENGLISH: The negative zombie argument has as premises that p∧¬q is ideally negatively conceivable, that what is ideally negatively conceivable is possible, and that Physicalism is incompatible with p∧¬q being possible and as conclusion that Physicalism is false. In the argument, p is the conjunction of the fundamental physical truths and laws and q is an arbitrary phenomenal truth. A sentence φ is ideally negatively conceivable if and only if an ideal reasoner does not believe that ¬φ on a priori reflection. The argument presupposes a version of the scrutability thesis stating that, for all φ that supervene on p, the ideal reasoner believes that p → φ on a priori reflection. In this paper, I argue that, given relevant interpretation of probabilities, the ideal reasoner believes truly, for all φ, that p → pr(φ) = x on a priori reflection. But then, depending on the value of pr(q) and the correlations between q and other sentences, the ideal reasoner also believes (probably, truly) that p → q on a priori reflection. For some relevant qs, p∧¬q is not ideally negatively conceivable and the zombie argument has a false premise. The choice of an adequate q depends on empirical information, what makes the zombie argument neither conclusive nor a priori

O Que (e Como) Estava Pensando?: Sobre Memória de Pensamentos Passados

Recent philosophical and psychological researches show that memory, not only stores information but also process it. It's possible one to have a meta-representational memory despite the propositional content and attitude of the present meta-representation being different from the propositional content and attitude of the thought that the meta-representation is causally derived. So, the question is: if we take for granted that this kind of memory doesn't require content or attitude identity, what is the permissible range of aberration between the original content and the memory content? This paper proposes some conditions to define when a present meta-representation has the status of memory of a past thought, despite the difference of content or attitude. The condition for diachronic content similarity is the same proposed by Sven Bernerker. The attitude condition is a new one: the attitude that S thinks (at t2) himself having taken (at t1) towards p and the attitude that S took at t1 towards p* are sufficiently similar if and only if they are the same or the attitude of the present thought is entailed by the past attitude

Epistemic Sanity or Why You Shouldn't be Opinionated or Skeptical

I propose the notion of ‘epistemic sanity’, a property of parsimony between the holding of true but not false beliefs and the consideration of our cognitive limitations. Where ‘alethic value’ is the epistemic value of holding true but not false beliefs, the ‘alethic potential’ of an agent is the amount of extra alethic value that she is expected to achieve, given her current environment, beliefs, and reasoning skills. Epistemic sanity would be related to the holding of (true or false) beliefs that increase the agent's alethic potential (relevant beliefs) but not of beliefs that decrease it (this is related to cognitive parsimony). Suspension of judgment, forgetting, and clutter avoidance are the main contributors to an agent's epistemic sanity, where this paper focuses on suspension. I argue that rational suspension favors the holding of true and relevant beliefs, which is not the case for the extremes of opinionation (no suspension) and skepticism (general suspension). In the absence of evidence, opinionated agents are often forced to rely on principles such as the principle of indifference, but suspension dominates indifference in terms of alethic value in some conditions. A rational agent would only find it beneficial to adopt skepticism if she considers herself to be an anti-expert about her entire agenda, but then ‘flipping’ beliefs maximizes expected alethic value in relation to skepticism. The study of epistemic sanity results in an ‘impure’ veritism, which can deal with some limitations of veritism (e.g., explaining the existence of false but relevant beliefs)