'Methinks I am like a man, who having narrowly escap'd shipwreck', David Hume writes in A Treatise of Human Nature, 'has yet the temerity to put out to sea in the same leaky weather-beaten vessel, and even carries his ambition so far as to think of compassing the globe'. With these words, Hume begins a memorable depiction of the crisis of philosophy and his turn to moral and political philosophy as the path forward. In this groundbreaking work, Thomas...