This collection of thirteen original essays by such well-known philosophers as Thomas Nagel, Peter Singer, J.O. Urmson, David A.J. Richards, James Griffin, R.B. Brandt, John C. Harsanyi, T.M. Scanlon, and others discusses the philosophy of R.M. Hare put forth in his book Moral Thinking, including his thoughts on universalizability, moral psychology, and the role of common-sense moral principles. In addition, Professor Hare responds to his critics with an essay and a detailed, point-by-point criticism.