The author begins by distinguishing six fundamental issues on the metaphysics of individuality. He then proceeds to examine the relation among these issues and to demonstrate that ignorance of the interrelationships has caused confusion in philosophy. In spite of the intricacy of the subject matter, the discussion is always clear, the arguments explicitly evaluated, and the solutions original. In addition, Gracia has assembled an array of historical and contemporary information, from Plato to Strawson, that is unavailable elsewhere.