William Seager

The goal of standard semantics is to provide truth conditions for the sentences of a given language. Probabilistic Semantics does not share this aim; it might be said instead, if rather cryptically, that Probabilistic Semantics aims to provide belief conditions.The central and guiding idea of Probabilistic Semantics is that each rational individual has ‘within’ him or her a personal subjective probability function. The output of the function when given a certain sentence as input represents the degree of likelihood which the individual would assign to that sentence. One can characterize these functions via a set of axioms, and in the terms of this defined structure develop probabilistic analogues of all important semantical notions. Then, dealing with ‘being given probability 1’ instead of ‘truth,’ one can proceed to give a completely adequate semantics for the particular language under consideration. The axioms delimiting the class of probability functions are, in fact, chosen with this goal and language in mind.

The apparent 'flow' of time is one of its most mysterious features, and one which discomforts both scientists and philosophers. One of the most striking assaults upon it is McTaggart's argument that the idea of temporal flow is demonstratively incoherent. In this paper I first urge that the idea of temporal flow is an important part of our intuitive understanding of time, underpinning several of our notions about rationality and time. Second, I try to undercut McTaggart's argument by showing that it is not temporal flow which is illusory but rather the vicious regress McTaggart saw in that idea. A steadfast clinging to the notion of now, along with an analysis of McTaggart's argument reveals that the regress halts after but two steps.

This note aims to make more familiar to philosophers yet another bizarre quantum mechanical effect with disturbing metaphysical implications. It is possible to modify the classic double-slit experiment so that one can register the path of a particle to determine which slit it passes through, and then erase this registered information so that the interference effects which would normally disappear upon registration of the "which path" information are reconstituted. Thus the "trajectory" of particles can be effected by temporally and spatially distant operations on the slit detectors. Nonetheless, no untoward effects (such as superluminal signalling) can result from the operation of the eraser

Brook and Raymont do not assert that self-representing representations are sufficient to generate consciousness, but they do assert that they are necessary, at least in the sense that self-representation provides the most plausible mechanism for generating conscious mental states. I argue that a first-order approach to consciousness is equally capable of accounting for the putative features of consciousness which are supposed to favor the self-representational account. If nothing is gained the simplicity of the first-order theory counts in its favor. I also advance a speculative proposal that we are never aware of any distinctively mental attributes of our own states of consciousness except via an independent act of reflective conceptualization, although this goes rather farther than the first-order theory strictly requires.

Jerry Fodor has recently proposed a new entry into the list of information based approaches to semantic content aimed at explicating the general notion of representation for both mental states and linguistic tokens. The basic idea is that a token means what causes its production. The burden of the theory is to select the proper cause from the sea of causal influences which aid in generating any token while at the same time avoiding the absurdity of everything's being literally meaningful. I argue that a detailed examination of the theory reveals that neither burden can be successfully shouldered.

Our knowledge forms a highly interconnected and dynamically changing body of propositions. One obviously important way that knowledge changes is via rational inference, based either upon new insight into the content of what we already know or upon new knowledge provided by the senses. The most obvious codification of the acceptability of inference driven knowledge growth is the so-called known entailment closure principle, the principle that if S knows that p and knows that p implies q then S knows that q, or, more formally.

Donald Davidson espouses two fundamental theses about the individuation of mental events. The thesis of causal individuation asserts that sameness of cause and effect is sufficient and necessary for event identity. The thesis of content individuation gives only a sufficient condition for difference of mental events: if e and f have different contents then they are different mental events. I argue that given these theses, psychological externalism--the view that mental content is determined by factors external to the subject of the relevant mental events--entails that the token identity theory is false

The doctrine of physicalism can be roughly spelled out simply as the claim that the physical state of the world determines the total state of the world. However, since there are many forms of determination, a somewhat more precise characterization is needed. One obvious problem with the simple formulation is that the traditional doctrine of epiphenomenalism holds that the mental is determined by the physical (and epiphenomenalists need not assert that there are any properties except mental and physical ones, so one can freely add to epiphenomenalism the claim that everything is determined by the physical state of the world). However, the orthodox view, which seems obviously correct, is that physicalists would and should balk at the claim that epiphenomenalism is a form of physicalism. The philosophical zombie thought experiment vividly reveals exactly why epiphenomenalism is not a version of physicalism. According to traditional epiphenomenalism the determination relation in question is causation, and causal relations do not hold with full necessity. They hold with at most nomological necessity. Thus there is a possible world, w, in which the causal laws (or, if one prefers a more Humean approach, where the cosmic regularities) are different in such a way that the physical states which in the actual world cause mental states either cause no mental states at all in w (the zombie option) or cause aberrant mental states (the inverted spectrum option). Why should the physicalist care about this ‘mere possibility’? Because it shows that the mental can vary independently of the physical and there can be no better demonstration of ontological distinctness 1 than independent variation. Therefore, physicalism requires that the sort of determination at issue must exhibit maximum modal force; it must be absolutely impossible for the mental to vary without attendant, determining physical variation (let us label this relation ‘logical determination’). I think the best way to state physicalism which meets this constraint is in terms of what are called minimal physical duplicates (MPDs) of possible worlds (an approach pioneered by David Lewis, see Lewis (1983b); see also Jackson (1998) and Chalmers and Jackson (2001))..

It has been argued that Psychological Externalism is irrelevant to psychology. The grounds for this are that PE fails to individuate intentional states in accord with causal power, and that psychology is primarily interested in the causal roles of psychological states. It is also claimed that one can individuate psychological states via their syntactic structure in some internal "language of thought". This syntactic structure is an internal feature of psychological states and thus provides a key to their causal powers. I argue that in fact any syntactic structure deserving the name will require an external individuation no less than the semantic features of psychological states

RésuméFred Dretske a développé, à titre de composante de sa théorie de la conscience, une théorie de I'introspection. Celle-ciprésente une plausibilityé indépendante, elle résiste à des objections qui affectent nombre d'autres théories et elle suggère des liens très féconds dans plusieurs domaines de la science cognitive. La version qu'en donne Dretske est restreinte à la connaissance introspective des états perceptuels. Mon objectif ici est d'étendre la théorie à tous les états mentaux. Le mécanisme qui est fondamental dans cette approche est celui de la «conscience déplacée», c'est-à-dire le fait d'en venir à connaître quelque chose via l'expérience consciente que nous avons de quelque chose d'autre. Nous atteignons la connaissance introspective par l'application à notre propre expérience consciente du monde (et de nos corps) de la connaissance que nous avons de ce qui est de l'ordre du mental.

THIS ARTICLE ARGUES THAT WEAK SUPERVENIENCE IS\nSUFFICIENTLY STRONG TO ESTABLISH A REASONABLE AND PLAUSIBLE\nMATERIALISM. SUPERVENIENCE IS A RELATION BETWEEN FAMILIES\nOF PROPERTIES, SUCH THAT, ROUGHLY SPEAKING, FAMILY A\nSUPERVENES ON FAMILY B IF ANY OBJECTS WHICH ARE\nINDISCERNIBLE WITH RESPECT TO B ARE THEREBY INDISCERNIBLE\nWITH RESPECT TO A. WEAK SUPERVENIENCE IS SUPERVENIENCE\nRESTRICTED TO ONE POSSIBLE WORLD; STRONG SUPERVENIENCE IS A\n"NECESSARY" SUPERVENIENCE EXTENDING ACROSS SOME PRINCIPLED\nSET OF POSSIBLE WORLDS. THESE NOTIONS ARE MADE SOMEWHAT\nMORE RIGOROUS FOLLOWING JAEGWON KIM'S DEVELOPMENT OF THEM.\nKIM HAS ARGUED THAT ONLY STRONG SUPERVENIENCE CAN GROUND A\n'ROBUST' MATERIALISM, SO THE ARTICLE BEGINS BY CRITICIZING\nHIS ARGUMENTS FOR THIS POSITION. IT ARGUES THAT ANY FORM OF\nSTRONG SUPERVENIENCE IS IN FACT TOO STRONG TO CHARACTERIZE\nMATERIALISM AS IT IS NORMALLY CONCEIVED, FOR MATERIALISM IS\nNEITHER LOGICALLY NOR PHYSICALLY NECESSARY. BUT THE DAY IS\nSAVED AS WEAK SUPERVENIENCE CAN BE SHOWN TO BE JUST\nSUFFICIENTLY STRONG TO GROUND MATERIALISM. IN PARTICULAR,\nIT IS SHOWN THAT SUPERVENIENCE CAN SUPPORT COUNTERFACTUALS\nWITHOUT REQUIRING ANY NOTION OF "NECESSARY"\nSUPERVENIENCE

There are many possible forms of panpsychism. In this paper, I discuss a type of panpsychism in which the complex mental states of higher-level entities emerge from a system, or organization, of fundamental entities which possess extremely simple forms of mentality. I argue that this sort of panpsychism is surprisingly plausible, especially in light of the notorious difficulties raised by consciousness. Emergentist panpsychism faces a distinctive challenge, however. In so far as panpsychism embraces emergentism of the mental, a purely physicalist emergence seems to be metaphysically more economical. I will argue that a basic analysis of emergence throws this claim into doubt

_Metaphysics of Consciousness_ opens with a development of the physicalist outlook that denies the need for any explanation of the mental. This "inexplicability" is demonstrated not to be sufficient as refutation of physicalism. However, the inescapable particularity of modes of consciousness appears to overpower this minimal physicalism. This book proposes that such an inference requires either a wholly new conception of how consciousness is physical or a deep and disturbing new kind of physical inexplicability.