At long last a comprehensive tool in English for a better understanding of the most basic terms in Aristotle s philosophy. Interested readers, students and scholars of philosophy and of the general intellectual background of Western culture need no longer be handicapped by a lack of knowledge of Greek and Latin. A careful comparison of the original Greek, medieval and Renaissance Latin translations and a reappraisal of English usage make this work a definitive source for the precise grasp of what has been the historical Aristotle as far as the documents permit one to judge.