But seeing that Xenocrates won to his opinions several of the most eminent philosophers, while he defined the substance of the soul to be number moved by itself; and that many adhered to Crantor the Solian, who affirmed the soul to consist partly of an essence perceptible to the mind, partly of a nature concerned with sensible things and subject to opinions; I am apt to believe that the perspicuity of these matters clearly dilucidated will afford you a fair entrance into the knowledge of the rest. 2. Nor does either of the two conjectures require many words of explanation. For the one side pretends that by the mixture of the divisible and indivisible substance no other thing is meant than the generation or original of number, seeing that the unit is undividable but multitude is subject to division; however, that out of these is begot number, unity terminating plurality and putting a period to infinity, which they call the unlimited binary. This binary Zaratas, the scholar of Pythagoras, named the mother, but the unit the father of number; and therefore he believed those numbers were the best which approached nearest in resemblance to the unit. Nevertheless, this number cannot be said to be the soul; for it neither has the power to move, neither can it be moved. But the Same and the Other being blended together, of which one is the original of motion and mutation, the other of rest and stability, from these two springs the soul, which is no less active or passive itself to stay or to be stayed, than to move or to be moved. But the followers of Crantor, supposing the proper function of the soul to consist in judging of those things which are discernible to the understanding and those which are liable to sense, as also of the differences and similitudes of these things, as well in themselves as in reference one to another, allege the soul to be composed of all, to the end she may have a true knowledge of the whole. Now the things of which the All is composed are fourfold,—the intelligible nature, always immutable and still the same, and the sensitive nature, which is passive and subject to alteration; and also the nature of the Same, and the nature of the Other, in regard the two former in some measure participate also of diversity and identity. 3. All these philosophers likewise equally hold that the soul neither derives its beginning from time nor is the product of generation, but that it is endued with several faculties and virtues, into which Plato, as it were, melting and dissolving its substance for contemplation’s sake, supposes it in his discourse to have had its original from procreation and mixture.