ABSTRACT
In early 1734, David Hume wrote a letter that he did not sign, to a physician whom he did not name. This letter provides a window into an obscure period of Hume’s life, as well as into the alien world of early eighteenth-century psychological science. I use this episode in Hume’s life to provoke thought about the distinction between vice and mental illness, as well as our responses to both problems. In the first section, I explain the many obstacles to our understanding the condition of an eighteenth-century sufferer from the “disease of the learned.” In the second section, I explain how Hume’s philosophical psychology further complicates our understanding of mental illness, particularly with respect to the attempt to distinguish it from vice. I infer that a Humean distinction between vice and mental illness must be vague, lying along a wide continuum. Finally, I argue that the continuity between these concepts might actually be helpful, in allowing us to draw on Hume’s suggestions for improving the passions in cases across the continuum. The third section of the chapter includes a sketch of a method for such improvement—the cultivation of aesthetic passions to ameliorate a kind of bipolarity.
