or in his having the skill of a flute player, if he does not play the flute? or of his knowing the harp, if he does not strike it? or, in short, what good is there in any artist whatever, if he does not exercise his art? for theoretical knowledge, without putting it in practise, is of no advantage whatever to those who possess it. For a man, though skilful in the contest of the pancratium, or in boxing, or in wrestling, would derive no advantage from his athletic prowess if his hands were tied behind him; and he who was thoroughly practised in running would derive no advantage from his fleetness of foot if he were afflicted with the gout, or if he were to meet with any other injury to his feet. And the light of the soul, which is the most brilliant and the most like the sun, is knowledge; for as the eyes are lightened up by beams, so is the mind made brilliant by wisdom, and becomes gradually accustomed to see more acutely from being continually anointed with new speculations.
Therefore, Nachor is interpreted "a cessation from light,"

 1 Chronicles vii. 14. 
 
very naturally; for, inasmuch as he is a relation of the wise Abraham, he partakes of that light which is according to wisdom; but inasmuch as he did not join him in his emigration from the created to the uncreated being, from the world to the Creator of the world, he has acquired only a lame and imperfect knowledge, intermittent and delaying, or rather put together like a lifeless statue; for he does not depart and quit his abode in the Chaldaean country, that is to say, he does not separate himself from the speculations concerning astronomy; honouring that which is created rather than him who created it, and the world in preference to God; or rather, I should say, looking on the world itself as an absolute independent God, and not as the work of an absolute God.
 And he takes Milcah for his wife, not being some queen who by the dispensations of fortune governs some nation of men, or some city, but only one who bears a common name, the same as here. For, just as a person would not be widely wrong who called the world, as being the most excellent of all created things, the king of the objects of the external sense; so, also, one may call the knowledge which is conversant about the heaven, which knowledge those who study astronomy and the Chaldaeans possess in an eminent degree, the queen of all the sciences.