We think and talk about things that do not exist—or so it seems. We say that Santa Claus lives on the North Pole and that unicorns are white. We admire Sherlock Holmes or judge him to be more clever than J. Edgar Hoover. People search for the Northwest Passage and the Fountain of Youth. They dream about lottery winnings and fear disasters that do not materialize. A childless couple hopes for a daughter. So, according to Alexius Meinong and others, there are things that do not exist. Even to deny that Santa Claus or the Fountain of Youth exists, we must be able, it seems, to identify what it is whose existence we are denying.

Bertrand Russell's rejection of this line of thought is well known. Sentences containing expressions that appear to denote nonexistents are to be paraphrased, in accordance with his theory...