Aristotle attaches particular significance to the homomyny of many of the central concepts in philosophy and science: that is, to the diversity of ways of being that are denoted by a single concept. Shields here investigates and evaluates Aristotle's approach to questions about homonymy, characterizing the metaphysical and semantic commitments necessary to establish the homonymy of a given concept. Then, in a series of case studies, he examines in detail some of Aristotle's principal applications of homonymy--to the body, sameness and oneness, life, goodness, and being. This first full-length study of a central aspect of Aristotle's thought will interest philosophers working in a number of areas.