Aristotle is widely regarded as the greatest of all philosophers; indeed, he is traditionally referred to simply as `the philosopher'. Today, after more than two millennia, his arguments and ideas continue to stimulate philosophers and provoke them to controversy. In this book J.L. Ackrill conveys the force and excitement of Aristotle's philosophical investigations, thereby showing why contemporary philosophers still draw from him and return to him. He quotes extensively from Aristotle's works in his own notably clear English translation, and a picture emerges of a lucid, lively, subtle and tough-minded thinker of astonishing range and penetration. Professor Ackrill identifies many striking connections between Aristotle's ideas and ideas in recent philosophy; he also raises philosophical questions of his own, and exemplifies the way in which Aristotle can still be argued with and learned from.