Berit Brogaard

Since the publication of David Lewis’ Counterfactuals, the standard line on subjunctive conditionals with impossible antecedents (or counterpossibles) has been that they are vacuously true. That is, a conditional of the form ‘If p were the case, q would be the case’ is trivially true whenever the antecedent, p, is impossible. The primary justification is that Lewis’ semantics best approximates the English subjunctive conditional, and that a vacuous treatment of counterpossibles is a consequence of that very elegant theory. Another justification derives from the classical lore than if an impossibility were true, then anything goes. In this paper we defend non-vacuism, the view that counterpossibles are sometimes non-vacuously true and sometimes non-vacuously false. We do so while retaining a Lewisian semantics, which is to say, the approach we favor does not require us to abandon classical logic or a similarity semantics. It does however require us to countenance impossible worlds. An impossible worlds treatment of counterpossibles is suggested (but not defended) by Lewis (Counterfactuals. Blackwell, Oxford, 1973), and developed by Nolan (Notre Dame J Formal Logic 38:325–527, 1997), Kment (Mind 115:261–310, 2006a: Philos Perspect 20:237–302, 2006b), and Vander Laan (In: Jackson F, Priest G (eds) Lewisian themes. Oxford University Press, Oxford, 2004). We follow this tradition, and develop an account of comparative similarity for impossible worlds.

Ernest Sosa has argued that the relevant alternatives theory of knowledge has yet to overcome serious difficulties. The most serious difficulty is that of providing criteria for when a rival alternative to a claim is relevant. Without such criteria, the theory is ad hoc. I argue that most other externalist theories of knowledge, including Sosa's own, fall victim to this criticism. At the end of the paper I make a suggestion as to why Sosa's objection might not be as damaging as it at first seems.

While much has been written about whether visual perception is cognitively penetrable, the analogous question with respect to auditory perception has received very little attention. Here we argue that instances of top-down modulation of auditory processing, although extensive, do not constitute cases of cognitive penetration of auditory perception since the changes in the phenomenology of auditory perception caused by top-down influences cannot plausibly be attributed to the listeners’ discursive thoughts.

Naive realism is one of the oldest theories of perception. To a first approximation, naive realism is the view that perception is a direct relation between a subject and an object. Many historical philosophers (from Locke to Russell) argued that naive realism must be rejected on the grounds that hallucinations are perceptual experiences without an object. Contemporary philosophers have resurrected the theory by insisting that genuine cases of perception have a different structure or a different metaphysical status than non-genuine ones. This version of naive realism has come to be known as ‘disjunctivism’. Epistemological disjunctivism and disjunctivism about phenomenal belief, or what I shall call ‘Epistemological disjunctivism’, have also gained popularity in recent years. More recently disjunctivist accounts of bodily movements, abilities and reasons for action have entered the philosophical scene. This entry focuses on the contemporary debate about disjunctivism: its characterization, its motivation and its potential shortcomings.