The ought in thought: Logic and rational norms in Kant, the 'Tractatus', and beyond

Basic rules of valid inference are normative for belief: someone who knowingly believes contrary to such a rule, like modus ponens, is at fault for such belief. It follows that in thinking we are able to recognize instances of logically defective belief. How we are able to recognize such defectiveness, I call the problem of logical responsibility.;I examine a logical essentialist answer to this problem. Essentialism aims to describe the nature of logic and thought such that (i) thinking propositions in part involves recognizing the truth of those propositions as reasons for belief in the propositions they imply, and (ii) appreciating these reasons involves no cognitive achievement.;I examine Kant's and the early Wittgenstein's success in securing the essentialist's goals. Kant rests logical validity on the operations of the understanding in judgment. While this does ensure that (i) is true, it does so at the cost of explanatory circularity: recognition of the right reasons requires knowledge of the compatibility conditions of the understanding's operations. Therefore Kant fails to secure (ii).;Wittgenstein's Tractatus casts logical validity as merely an oblique and misleading way of characterizing the sense of jointly held propositions. Consequently, in holding propositions true we thereby hold true the propositions they imply. While this does not encounter the explanatory circularity of Kant's account, it does rely on a notion of sense that compromises (ii).;The view I propose rejects the assumption implicit in both Kant and Wittgenstein that logical validity can be explained by anything besides the rational compatibility of beliefs. I therefore characterize logical form as a linguistic tool that regiments rational relationships among propositions: we indicate these rational relationships by assigning them logical forms. Rational relationships, in turn, need no explanation, and in accord with (ii), no special knowledge, since the question of what makes a reason a reason is incoherent. Logical responsibility is then explained, for to give thoughts logical form just is to declare the rational relationships in which they stand.