Terence Penelhum has written extensively about the role of the idea of the self in Hume's account of the emotional and moral life of persons. Penelhum fails to notice, however, a change that takes place in the way that the idea of the self functions in Hume's account of the passions as that account evolved after the Treatise. This paper charts part of that evolution, and reflects on its significance for Hume's moral psychology.