 Kant’s notion of the free play of the faculties (sometimes referred to as the “harmony of the faculties”, or, more accurately the “free harmony” of the faculties) is probably the most central notion of his aesthetic theory. But what is it for the faculties of imagination and understanding to be in “free play”? Kant describes the imagination and understanding in this “free play” as freely harmonizing, without the imagination’s being constrained by the understanding as it is in cognition. Imagination in the free play, he says, conforms to the general conditions for the application of concepts to objects that are presented to our senses, yet without any particular concept being applied, so that imagination conforms to the conditions of understanding without the constraint of particular concepts. Given Kant’s view that concepts are, or at least correspond to, rules by which imagination “synthesizes” or organizes the data of sense-perception, this amounts to saying that imagination functions in a rule-governed way but without being governed by any rule in particular. The free play thus manifests, in Kant’s terms, “free lawfulness” or “lawfulness without a law”. But there is an apparent paradox in these characterizations which is left unaddressed by Kant’s own, largely metaphorical, explanations. It is left to commentators to try to explain how such an activity is intelligible and why, if it is indeed intelligible, it should give rise to, or be experienced as, a feeling of pleasure.