 Is Green’s perfectionist ethical theory dependent on his idealist metaphysics? If so, his perfectionism is hostage to his idealism, and doubts about his metaphysics may threaten his perfectionism. The Prolegomena to Ethics is Green’s most systematic work, and its structure might suggest that his perfectionist ethics of self-realization developed in Books II-IV rest on the idealist metaphysics defended in Book I. Certainly, many interpreters have accepted this kind of interdependence of Green’s metaphysics and ethics (e.g., Nicholson 2006, Armour 2006, and Mander 2006). However, several of Green’s writings in practical philosophy—notably, the essay “Liberal Legislation” and his Lectures on the Principles of Political Obligation—are not preceded by elaborate metaphysical discussions or arguments for absolute idealism. Moreover, even if we look at the Prolegomena, much of the argument against hedonism and in favor of perfectionism and the common good are intelligible and assessable without recourse to doctrines of absolute idealism. It’s true that self-consciousness plays a crucial role in both epistemic and practical agency. If idealism meant nothing more than the importance of self-consciousness to knowledge and moral personality, that might provide a kind of unity to Green’s metaphysics and ethics. It would represent the crucial idealist metaphysical claim as a comparatively modest and plausible one. But those claims about the importance of self-consciousness do not require any specifically idealist metaphysical claims that reality is limited to what is or can be an object of consciousness. Indeed, we have seen that there is a tension between Green’s moral psychology and his idealist metaphysics. Green thinks that responsibility consists in capacities for self-conscious reflection and assessment of one’s desires and options and that self-realization or perfection consists in the proper exercise of these reasons-responsive capacities. Green’s perfectionist ethics require that self-conscious minds play this causal role in the will and action, and that is inconsistent with the assumption in Green’s idealist metaphysics that self-conscious minds lie outside of space and time (Irwin 2009: §1235).