In The Problems of Philosophy Bertrand Russell referred to the distinction between appearance and reality as "one of the distinctions that cause most trouble in philosophy." Why it should cause trouble in philosophy, however, when it causes little or no trouble outside of philosophy, Russell did not say. The distinction has played an important part in the thinking of many philosophers, and some of them, including Russell, have employed it in curious ways to support odd and seemingly paradoxical claims. It may be this last fact that Russell had in mind when he spoke of trouble.

Before turning to some of its troublesome uses in philosophy, let us consider some of its relatively untroublesome uses in everyday discourse.

Looks and Appearances

There is a potentially troublemaking ambiguity in the term to appear and its cognates. (This ambiguity is not peculiar to English but is...