The eclipse of interest in Joseph Butler's analysis of the relation of conscience and action and the dismissal of his ethics on the grounds that the argument is flawed by circularity and/or the naturalistic fallacy are both a consequence of the failure of scholars to attend to the complex design of his work considered as a whole. The seldom studied Sermon XV is pivotal to understanding Butler's conception of failure and possibility. While it builds on the familiar arguments of Sermons (...) I-III, the last sermon sets aside the analogy of the watch to explore the problem of virtue in light of Old Testament wisdom narratives that establish the vanity of human endeavor and the limitations of the human condition. Sermon XV not only alters our reading of those that precede it but also binds Butler's reflections on ethics to his later reflections on religious truth. (shrink)