The history of the thesis of the guise of the good between Kant and Anscombe is not well understood. This article examines a notable disagreement over the thesis during this period, between Green and Sidgwick. It shows that Green accepts versions of the thesis concerning action and desire in one sense of 'desire', and that Sidgwick rejects the thesis concerning both action and desire. It then considers why Green accepts the thesis, and assesses Sidgwick's criticism of Green. Despite the appearance (...) of a mere clash of intuitions, an interesting rationale for the thesis can be found in Green’s theory of free will and moral responsibility, of which I defend a broadly compatibilist interpretation. (shrink)