We find that the special prerogative he has received is mind, habituated to apprehend the natures both of all material objects and of things in general. For as sight holds the leading place in the body, and the quality of light holds the leading place in the universe, so too in us the dominant element is the mind.
[46] For mind is the sight of the soul, illuminated by rays peculiar to itself, whereby the vast and profound darkness, poured upon it by ignorance of things, is dispersed. This branch of the soul was not formed of the same elements, out of which the other branches were brought to completion, but it was allotted something better and purer, the substance in fact out of which divine natures were wrought. And therefore it is reasonably held that the mind alone in all that makes us what we are is indestructible.
[47] For it is mind alone which the Father who begat it judged worthy of freedom, and loosening the fetters of necessity, suffered it to range as it listed, and of that free-will which is His most peculiar possession and most worthy of His majesty gave it such portion as it was capable of receiving. For the other living creatures in whose souls the mind, the element set apart for liberty, has no place, have been committed under yoke and bridle to the service of men, as slaves to a master. But man, possessed of a spontaneous and self-determined will, whose activities for the most part rest on deliberate choice, is with reason blamed for what he does wrong with intent, praised when he acts rightly of his own will.
[48] In the others, the plants and animals, no praise is due if they bear well, nor blame if they fare ill: for their movements and changes in either direction come to them from no deliberate choice or volition of their own. But the soul of man alone has received from God the faculty of voluntary movement, and in this way especially is made like to Him, and thus being liberated, as far as might be, from that hard and ruthless mistress, necessity, may justly be charged with guilt, in that it does not honour its Liberator. And therefore it will rightly pay the inexorable penalty which is meted to ungrateful freedmen.
[49] Thus God “had it in His mind and bethought Him” not now for the first time, but ever from of old—a thought that was fixed and steadfast—“that He had made man,” that is He thought of what nature He had made him. He had made him free and unfettered, to employ his powers of action with voluntary and deliberate choice for this purpose, that, knowing good and ill and receiving the conception of the noble and the base, and setting himself in sincerity to apprehend just and unjust and in general what belongs to virtue and what to vice, he might practise to choose the better and eschew the opposite.
[50] And therefore we have an oracle of this kind recorded in Deuteronomy. “Behold, I have set before thy face life and death, good and evil; choose life” (Deut. 30:15, 19). So then in this way He puts before us both truths; first that men have been made with a knowledge both of good and evil, its opposite; secondly, that it is their duty to choose the better rather than the worse, because they have, as it were, within them an incorruptible judge in the reasoning faculty, which will accept all that right reason suggests and reject the promptings of its opposite.