Wittgenstein on Logic The aim of this monograph is to examine Wittgenstein’s philosophy of logic, early and late, from the perspective a particular brand of naturalism called ‘second philosophy’. The Second Philosopher holds a roughly empirical account of logical truth derived from Kant: logic is grounded in the structure of our contingent world; our basic cognitive machinery is tuned by evolutionary pressures to detect that structure where it occurs. The early Wittgenstein of the Tractatus also links the logical structure of representation with worldly structure, but insists that the sense of our representations must be given prior to, independently of, any facts about how the contingent world happens to be. When that requirement is removed– as the naturalistically minded will argue that it should be – the Tractarian position approaches the Second Philosopher’s: logic is grounded in the structure of the world; our representational systems reflect that structuring.