This treatise sets out the case for the internality of Forms and argues for the necessary existence of an absolutely simple and transcendent first principle of all, the One or the Good. Not only Intellect and the Forms, but everything else depends on this principle for their being.

Lloyd P. Gerson is professor of philosophy at the University of Toronto. He is the author or editor of some 20 books and approximately 200 articles and reviews, mainly in ancient philosophy. He works especially on Plato, Aristotle, and Plotinus. He has also translated woks of Aristotle (with H. G. Apostle), Hellenistic philosophy (with Brad Inwood), and Neoplatonic philosophy (with John Dillon). Among his authored works are God and Greek Philosophy (Routledge, 1990), Plotinus. (Arguments of the Philosophers Series. Routledge, 1994), Knowing Persons. A Study in Plato (Oxford, 2004), Aristotle and Other Platonists (Cornell, 2005), Ancient Epistemology (Cambridge, 2009).