γνῶθι σεαυτόν …

… Review of Simon Blackburn, 'Mirror, Mirror: The Uses and Abuses of Self-Love' @insidehighered.

Writing in the 18th century, David Hume found the self to be elusive: “For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure…. When my perceptions are removed for any time, as by sound sleep; so long as I am insensible of myself, and may truly be said not to exist.”

Well, the self is elusive, to be sure, at least if you want to define it, but to assert that one "may truly be said not to exist" when one is sound asleep is patently ridiculous, whether said by Hume or anyone else.