In this groundbreaking work, Thomas W. Merrill shows how Hume’s turn is the core of his thought, linking Hume’s metaphysical and philosophical crisis to the moral-political inquiries of his mature thought. Merrill shows how Hume’s comparison of himself to Socrates in the introduction to the Treatise illuminates the dramatic structure and argument of the book as a whole, and he traces Hume’s underappreciated argument about the political role of philosophy in the Essays.