LXXIII. Of existing things, some are divisible and some indivisible. Again, those which are divisible, consist either of similar or of dissimilar parts. Those which are indivisible are such as have no separate parts, and are not formed by any combination, such as unity, a point, or a sound. But those are divisible which are formed by some combination; as, for instance, syllables, and symphonies, and animals, and water, and gold. These too consist of similar parts, which are made up of particles resembling one another, and of which the whole does not differ from any part, except in number. As for instance, water and gold, and everything which is fusible, and so on. And these consist of dissimilar parts, which are made up of various things not resembling one another; as for instance, a house, and things of that sort; so that of existing things, some are divisible and others indivisible. And of those which are divisible, some consist of similar and others of dissimilar parts. LXXIV. Again, of existing things, some are spoken of as having an independent, and some only a relative existence. Those which are spoken of as having an independent existence, are those which require nothing else to be added to them, when we are explaining their nature; as man, a horse, and the other animals; for these have no need of any additional explanation. But those things are said to have a relative existence which do require some additional explanation. As for instance, that which is greater than something else, or less, or swifter, or more beautiful, and so on. For that which is greater, is greater than something which is less; and that which is swifter, is swifter than something else. So that, of existing things, some are spoken of as independently, and other relatively. And thus he divided them at first, according to Aristotle. LXXV. There was also another man of the name of Plato, a philosopher of Rhodes, a disciple of Panætius, as Seleucus, the grammarian says in the first book of his treatise on Philosophy; and another was a Peripatetic, a pupil of Aristotle; and there was a third, a pupil of Praxiphanes; and there was besides all these, the poet of the Old Comedy. BOOK IV. LIFE OF SPEUSIPPUS. I. The long account which I have given of Plato was compiled to the best of my power, and in it I collected with great zeal and industry all that was reported of the man. II. And he was succeeded by Speusippus, the son of Eurymedon, and a citizen of Athens, of the Myrrhinusian burgh, and he was the son of Plato’s sister Potone. III. He presided over his school for eight years, beginning to do so in the hundred and eighth olympiad. And he set up images of the Graces in the temple of the Muses, which had been built in the Academy by Plato.