INTRODUCTION
II.—Theophrastus' Life and Works
Such information as we possess concerning the life of Theophrastus comes mainly from Diogenes Laertius' Lives of the Philosophers, compiled at least four hundred years after Theophrastus' death; it is given therefore here for what it may be worth; no intrinsic improbability in most of what Diogenes records.
He was born in 370 b.c. at Eresos in Lesbos; at an early age he went to Athens and there became a pupil of Plato. It may be surmised that it was from him that he first learnt the importance of that principle of classification which runs through all his extant works, including even the brochure known as the 'Characters' (if it is rightly ascribed to him), and which is ordinarily considered as characteristic of the teaching of his second master Aristotle. But in Plato's own later speculations classification had a very important place, since it was by grouping things in their 'natural kinds' that, according to his later metaphysic, men were to arrive at an adumbration of the 'ideal forms' of which these kinds are the phenomenal counterpart, and which constitute the world of reality. Whether Theophrastus gathered the principle of classification from Plato or from his fellow-pupil Aristotle, it appears in his hand to have been for the first time systematically applied to the vegetable world. Throughout his botanical
