Explanation and the Language of Thought

In this paper we argue that the insistence by Fodor et. al. that the Language of Thought hypothesis must be true rests on mistakes about the kinds of explanations that must be provided of cognitive phenomena. After examining the canonical arguments for the LOT, we identify a weak version of the LOT hypothesis which we think accounts for some of the intuitions that there must be a LOT.We then consider what kinds of explanation cognitive phenomena require, and conclude that three main confusions lead to the invalid inference of the truth of a stronger LOT hypothesis from the weak and trivial version. These confusions concern the relationship between syntax and semantics, the nature of higher-level causation in cognitive science, and differing roles of explanations invoking intrinsic structures of minds on the one hand, and aetiological or evolutionary accounts of their properties on the other.We are indebted to Frank Jackson, Philip Pettit, Huw Price, and Kim Sterelny for their generous and useful comments on an earlier draft of this paper, and to discussions with Martin Davies on these and related issues.