Hume’s ethics is concerned not only with the metaphysical status of moral qualities but equally, if not more, with the problem of determining to what extent and under what conditions issues of moral disagreement and inquiry can be decided by rational argumentation. This paper argues that Hume’s solution to the second problem is a form of perspectivism: the rational decidability of moral issues depends on the existence of shared perspectives, or sets of assumptions and correlated dispositions to feelings, and is largely independent of the metaphysical status of moral qualities. An issue of disagreement may thus be rationally decidable among people with certain dispositions to feeling but not among others. A similar perspectivist reading is suggested for Hume’s analysis of knowledge about causes and effects.