The guise of the good doctrine is the view that whatever we desire, we desire it under the guise of the good, i.e. it appears good to us in some way. In this paper I first clarify the role that the doctrine of the guise of the good plays in the first step of J. S. Mill’s proof of the principle of utility (in which he shows that one’s happiness is desirable as an end). Then I provide textual evidence in (...) favour of ascribing the doctrine to Mill, arguing that he commits to it to the extent that he equates finding something pleasant and thinking it desirable. Finally I counter two potential sources of evidence against ascribing the guise of the good to Mill: apparent desires based on ‘fixed ideas’, and those habitual desires which are no longer associated with finding their objects pleasant. I argue that ‘fixed ideas’ do not feed actual desires, and that the habitual desires which seem to escape the guise of the good, even if not uncommon, have a secondary status as desires. (shrink)