Berit Brogaard

The paradox of knowability is a logical result suggesting that, necessarily, if all truths are knowable in principle then all truths are in fact known. The contrapositive of the result says, necessarily, if in fact there is an unknown truth, then there is a truth that couldn't possibly be known. More specifically, if p is a truth that is never known then it is unknowable that p is a truth that is never known. The proof has been used to argue against versions of anti-realism committed to the thesis that all truths are knowable. For clearly there are unknown truths; individually and collectively we are non-omniscient. So, by the main result, it is false that all truths are knowable. The result has also been used to draw more general lessons about the limits of human knowledge. Still others have taken the proof to be fallacious, since it collapses an apparently moderate brand of anti-realism into an obviously implausible and naive idealism.

This volume consists of the invited papers presented at the 23rd International Wittgenstein Conference held in Kirchberg, Austria in August 2000. Among the topics treated are: truth, psychologism, science, the nature of rational discourse, practical reason, contextualism, vagueness, types of rationality, the rationality of religious belief, and Wittgenstein. Questions addressed include: Is rationality tied to special sorts of contexts? ls rationality tied to language? Is scientific rationality the only kind of rationality? Is there something like a Western rationality? and: Could we genetically engineer human beings to be less wicked?

Lewis/Stalnaker semantics has it that all counterpossibles (i.e., counterfactual conditionals with impossible antecedents) are vacuously true. Non-vacuism, by contrast, says the truth-values of counterpossibles are affected by the truth-values of the consequents. Some counterpossibles are true, some false. Williamson objects to non-vacuism. He asks us to consider someone who answered ‘11’ to ‘What is 5 + 7?’ but who mistakenly believes that he answered ‘13’. For the non-vacuist, (1) is false, (2) true: (1) If 5 + 7 were 13, x would have got that sum right (2) If 5 + 7 were 13, x would have got that sum wrong Williamson is not persuaded by the initial intuitiveness of such examples: ... they tend to fall apart when thought through. For example, if 5 + 7 were 13 then 5 + 6 would be 12, and so (by another eleven steps) 0 would be 1, so if the number of right answers I gave were 0, the number of right answers I gave would be 1. (2006) That’s the whole argument—much of it implicit. Alan Baker’s critique (2007) of Brogaard and Salerno (2007) prompts us to say something less abbreviated about a less abbreviated form of Wiliamson’s argument. Then we further develop our (2007) counterfactual analysis of essense

Perspectivalism is a semantic theory according to which the contents of utterances and mental states (perhaps of a particular kind) have a truth-value only relative to a particular perspective (or standard) determined by the context of the speaker, assessor, or bearer of the mental state. I have defended this view for epistemic terms, moral terms and predicates of personal taste elsewhere (Brogaard 2008a, 2008b, forthcoming a). The main aim of this paper is to defend perspectivalism about color perception and color discourse. The content of color perception and color discourse, I will argue, has a truth-value only relative to an appropriate viewing condition and the perceiver, or a perceiver deferred to.