4 For the body is not possessed of greater power than the soul, since indeed the former is inspired, and vivified, and increased, and held together by the latter; but the soul possesses and rules over the body. It is doubtless retarded in its velocity, just in the exact proportion in which the body shares in its motion; but it never loses the knowledge which properly belongs to it. For the body may be compared to an instrument; but the soul is possessed of the reason of an artist.
As, therefore, the artist finds the idea of a work to spring up rapidly in his mind, but can only carry it out slowly by means of an instrument, owing to the want of perfect pliability in the matter acted upon, and thus the rapidity of his mental operation, being blended with the slow action of the instrument, gives rise to a moderate kind of movement [towards the end contemplated]; so also the soul, by being mixed up with the body belonging to it, is in a certain measure impeded, its rapidity being blended with the body's slowness.
Yet it does not lose altogether its own peculiar powers; but while, as it were, sharing life with the body, it does not itself cease to live. Thus, too, while communicating other things to the body, it neither loses the knowledge of them, nor the memory of those things which have been witnessed.
Source: Adversus haereses (New Advent)