 The question of how to understand the free play is complicated by a more general interpretive issue concerning the status of Kant’s “transcendental psychology”: this issue affects not only the interpretation of the free play in the third Critique, but also the appeal to activities of imagination and understanding in Kant’s account of the conditions of cognition in the first Critique, in particular in the Metaphysical Deduction and the Transcendental Deduction. Many commentators assume, whether tacitly or explicitly, that the free play of imagination and understanding represents a natural psychological process, taking place in time and thus subject to natural causal laws. But it is hard to reconcile this understanding of the free play with Kant’s appeal to it to justify the legitimacy of judgments of beauty, and more generally his claim to be offering a transcendental account of judgments of beauty, one which shows such judgments to be founded on an a priori principle. Guyer’s approach to the free play, from his 1979 onwards, has been thoroughly naturalistic; in his 2008 he offers a very explicit defence of this approach, arguing that we should reject Kant’s claim to establish an a priori or transcendental principle justifying judgments of beauty, and instead regard Kant’s theory of aesthetics as a contribution to the empirical psychology of taste. While this kind of view is rarely explicitly endorsed, many commentators do in fact offer accounts of the free play which at least resemble empirical psychological accounts, raising the question of how Guyer’s conclusion is to be avoided.