XVII. (77) And the most visible proof of this migration in which the mind quitted astronomy and the doctrines of the Chaldaeans, is this. For it is said in the scriptures that the very moment that the wise man quitted his abode, “God appeared unto Abraham,”{10}{#ge 12:7.} to whom, therefore, it is plain that he was not visible before, when he was adhering to the studies of the Chaldaeans, and attending to the motions of the stars, not properly comprehending any nature whatever, which was well arranged and appreciable by the intellect only, apart from the world and the essence perceptible by the outward senses. (78) But after he changed his abode and went into another country he learnt of necessity that the world was subject, and not independent; not an absolute ruler, but governed by the great cause of all things who had created it, whom the mind then for the first time looked up and saw; (79) for previously a great mist was shed over it by the objects of the external senses, which she, having dissipated by fervent and vivid doctrines, was scarcely able, as if in clear fine weather, to perceive him who had previously been concealed and invisible. But he, by reason of his love for mankind, did not reject the soul which came to him, but went forward to meet it, and showed to it his own nature as far as it was possible that he who was looking at it could see it. (80) For which reason it is said, not that the wise man saw God but that God appeared to the wise man; for it was impossible for any one to comprehend by his own unassisted power the true living God, unless he himself displayed and revealed himself to him.