for he is more inclined to endure toil, but the other is more fortunate, for he has another person as a teacher. But this man, by his own unassisted efforts, investigates, and inquires, and pushes his examination, investigating the mysteries of nature with great earnestness, and exerting continual and incessant labour.
 For this reason God, who never changes, altered the name of Abraham, since he was about to remain in a similar condition, in order that that which was to be firmly established might be confirmed by him who was standing firmly, and who was remaining in the same state in the same manner. But it was an angel who altered the name of Jacob, being the Word, the minister of God; in order that it might be confessed and ascertained, that there is none of the things whose existence is subsequent to that of the living God, which is the cause or unchangeable and unvarying firmness. ... but of that harmony which, as in a musical instrument, contains the intensity and relaxation of sounds so as to produce an artistical combination of melody.
 But, there being three leaders and authors of this race, the two at each extremity of it had their names changed, namely Abraham and Jacob: but the one in the middle, Isaac, always retained the same appellation. Why was this? Because both that virtue which is derived from teaching and that which is attained to by practise, admit of improvement and advancement: for the man who receives instruction desires a knowledge of those matters of which he is ignorant and he who applies himself to practise desires the crowns of victory, and the prizes which are proposed to his industrious and contemplation-loving soul. But the race which is self-taught and which derives all its learning from its own diligence, inasmuch as it exists rather by nature than by study, was at the very beginning introduced as equal, and perfect, and even, there being no number whatever deficient of those which tend to completeness.
 Nor indeed does Joseph have any such need, he who is the president of the necessities of the body; for he also changes his name, being called Psonthomphanech by the king of the country. And what the meaning of these names is we must explain; the name Joseph, being interpreted, signifies "an
 
addition." For things which are put by the side are an addition to those which exist by nature; for instance, gold, silver, possessions, revenues, the ministrations of servants, abundant treasure of heirlooms, and furniture, and other superfluities, and the infinite multitude of the different efficients of pleasure which some persons possess; the provider and superintendant of which was called Joseph, or addition, by a very felicitous nomenclature: since he had undertaken the superintendence of the things which were to be brought in from without, and added to the natural things previously existing in the course of nature. And the sacred scriptures testify that this is the case, showing that he was the purveyor of the food of all the corporeal region, Egypt, having stored it up in his treasure-houses.