Justificationism differs from realism about how linguistic meaning is given, and hence in its associated conception of truth, and in particular in rejecting bivalence. Empirical discourse differs from mathematical primarily in that an effective decision-procedure for an empirical statement may cease to be available at a later time. The contrast is not that empirical knowledge is derived from what is mind-dependent, namely perception, whereas mathematical knowledge is not so derived. Mathematical knowledge does not accrue simply because a proof exists: the (...) proof has to be understood and recognized to be valid. Most ordinary mathematical proofs are indirect: they supply an effective means, in principle, to construct a direct or canonical proof. An indirect justification for asserting an empirical statement does not, in general, supply a means for bringing into existence a direct justification; it merely provides a ground for supposing that a direct justification would be or have been available for someone suitably placed to make the necessary observations. But it is by what constitutes direct evidence for a statement that its meaning is given; a grasp of its meaning does not rest on an ability to survey all conceivable indirect evidence. A direct justification of an empirical statement of the kind capable of being used as a report of observation must be an actual or possible observation by a suitably placed observer. A possible observation need not be explained by means of a counterfactual: it may be taken as consisting of the appropriate physical stimuli. This way of understanding it evades all three of the untenable choices Peacocke offers the justificationist. Unlike mathematical ones, empirical statements are often justifiably asserted on probabilistic grounds. When the statement admits of a conclusive justification, probabilistic evidence will not figure as a direct justification for asserting it, and hence as determining its meaning, so no circularity is involved, as Peacocke charges. There may, however, be empirical statements that can neither be reports of observation nor admit of a conclusive justification. Such statements can be asserted only on inductive or abductive grounds; this goes to characterize their meanings. Their meanings must therefore be explained by specifying such grounds as the most direct justifications of them that can be given, although they are difeasible rather than conclusive. Peacocke appears to deny that there can be statements that transcend all possible verification. To vindicate such a view from a realist standpoint is surely very difficult: it requires a demonstration that we could not grasp what it would be for such a statement to be true. It is very obscure what a realist's conception of truth is. The principle of bivalence remains a strong mark of differentiation between a justificationist and a realist conception of truth; a clear argument why the principle should be accepted would greatly help to clarify how the realist conceives of truth. I enjoyed reading Peacocke's article, but remain as perplexed as I was before just how he does conceive of truth. (shrink)

Berkeley’s ‘master argument’ for idealism has been the subject of extensive criticism. Two of his strongest critics, A.N. Prior and J.L. Mackie, argue that due to various logical confusions on the part of Berkeley, the master argument fails to establish his idealist conclusion. Prior argues that Berkeley’s argument ‘proves too little’ in its conclusion, while Mackie contends that Berkeley confuses two different kinds of self-refutation in his argument. This paper proposes a defence of the master argument based on intuitionistic argument. (...) It begins by giving a brief exposition of the master argument and Prior's and Mackie's criticism. The following section explains why we might read the master argument along intuitionistic lines. The final section demonstrates that, according to intuitionistic logic, Berkeley's argument withstands the criticisms of Prior and Mackie. (shrink)

Judgement, perception, and other mental states and events have a minimal objectivity in this sense: making the judgement or being in the mental state does not in general thereby make the judgement correct or make the perception veridical. I offer an explanation of this minimal objectivity by developing a form of constitutive transcendental argument. The argument appeals to the proper individuation of the content of judgements and perceptions. In the case of the conceptual content of judgements, concepts are individuated by (...) their fundamental reference rules. Properly developed, this resource can be used against various forms of idealism, and to defend a conception of transcendental arguments that presupposes neither verificationism nor transcendental idealism. The article contrasts its approach with other recent transcendental treatments. It also addresses the relation between its argument and Principles of Significance. I close with a discussion of the right way of handling the extreme generality necessarily involved in transcendental reasoning. (shrink)

The present article aims to show that a subject can only fully grasp the concept of the past if she has some experiential, or recollective, memories of particular past events. More specifically, I argue that (1) in order for a subject to understand the concept of the past, it is necessary that the subject understand the concept of a particular past event in such a way that it might contribute to her understanding of the concept of the past. (2) But (...) then, in order for a subject to understand the concept of a particular past event in such a way that it might contribute to her understanding of the concept of the past, it is necessary that the subject have some recollective memories of particular past events. (C) Hence, a subject can only understand the concept of the past if she has some recollective memories of particular past events. I defend the premises of the present argument against various objections, indicate why we should accept both premises, and accordingly end by endorsing the argument's conclusion. (shrink)

Social choice and welfare economics are subjects at the frontier of many disciplines. Even if economics played the major role in their development, sociology, psychology and, principally, political science, mathematics and philosophy have been central for the manifold inventiveness of the employed methods and for the diversity of the studied topics. This phenomenon can be compared with game theory, a subject which has, of course, many connections with social choice and welfare. This fact is reflected by the disciplinary origins of (...) the contributors to the subject and, as an anecdote, by the disciplinary origins of the board of editors of this journal. Philosophers are expected to contribute mainly to the study of social justice and related ethical questions. But there is a tradition among logicians for studying voting theory. A famous example is C. L. Dodgson (Lewis Carroll), even though the complete works of Dodgson on voting occupy only a few pages. A major recent example is Michael Dummett. Michael Dummett is famous among social choice theorists for his joint paper with Robin Farquharson published in Econometrica in 1961. Later he wrote two important books on voting (Dummett (1984, 1997); for an overview see Salles (2006)). But it must be outlined that Michael Dummett is also, and above all, one of the greatest contemporary philosophers whose work on the German logician Frege, on intuitionism, realism, anti-realism, justificationism has been central for the development of analytical philosophy in the second part of the last century and in this century (an example is the Symposium in a recent issue of Mind (see Peacocke (2005) and Dummett (2005)). Sir Michael Dummett is Wykeham Professor of Logic emeritus at Oxford University. His interview was conducted at New College, Oxford in September 2004. (shrink)

I discuss three connections between Dummett's writings about time and philosophical aspects of physics. The first connection arises from remarks of Dummett's about the different relations of observation to time and to space. The main point is uncontroversial and applies equally to classical and quantum physics. It concerns the fact that perceptual processing is so rapid, compared with the typical time-scale on which macroscopic objects change their observable properties, that it engenders the idea of a `common now', spread across space. (...) The other two connections are specific to quantum theory, as interpreted along the lines of Everett. So for these two connections, the physics side is controversial, just as the philosophical side is. In Section 3, I connect the subjective uncertainty before an Everettian `splitting' of the multiverse to Dummett's suggestion, inspired by McTaggart, that a complete, i.e. indexical-free description of a temporal reality is impossible. And in Section 4, I connect Barbour's denial that time is real---a denial along the lines of Everett, rather than McTaggart---to Dummett's suggestion that statements about the past are not determinately true or false, because they are not effectively decidable. (shrink)

Thesis (Ph.D.)--University of Hawaii at Manoa, 2008.