The Logic of Human Personality shows how the ancient definition of person remains useful today, and explains how it happened to fall into disuse. The method of using the categories of Aristotle is illustrated by showing how action, relation, and time as well as the fundamental category of substance, can help us understand what it is to be a person. The Logic of Human Personality agrues, against Mill and others who have found Aristotle's categories unsatisfactory, that in fact they are useful for much psychological and anthropological research today, particularly in the intercultural field. Mary L. O'Hara is Visiting Scholar at the College of St. Catherine, St. Paul, Minnesota.