A Treatise on the Soul

Besides, it would be a harsh and absurd proceeding to exempt anything from the class of corporeal beings, on the ground that it is not exactly like the other constituents of that class. And where individual creatures possess various properties, does not this variety in works of the same class indicate the greatness of the Creator, in making them at the same time different and yet like, amicable yet rivals? Indeed, the philosophers themselves agree in saying that the universe consists of harmonious oppositions, according to Empedocles' (theory of) friendship and enmity.

Thus, then, although corporeal essences are opposed to incorporeal ones, they yet differ from each other in such sort as to amplify their species by their variety, without changing their genus, remaining all alike corporeal; contributing to God's glory in their manifold existence by reason of their variety; so various, by reason of their differences; so diverse, in that some of them possess one kind of perception, others another; some feeding on one kind of aliment, others on another; some, again, possessing visibility, while others are invisible; some being weighty, others light.

They are in the habit of saying that the soul must be pronounced incorporeal on this account, because the bodies of the dead, after its departure from them, become heavier, whereas they ought to be lighter, being deprived of the weight of a body— since the soul is a bodily substance. But what, says Soranus (in answer to this argument), if men should deny that the sea is a bodily substance, because a ship out of the water becomes a heavy and motionless mass? How much truer and stronger, then, is the soul's corporeal essence, which carries about the body, which eventually assumes so great a weight with the nimblest motion!

Again, even if the soul is invisible, it is only in strict accordance with the condition of its own corporeality, and suitably to the property of its own essence, as well as to the nature of even those beings to which its destiny made it to be invisible. The eyes of the owl cannot endure the sun, while the eagle is so well able to face his glory, that the noble character of its young is determined by the unblinking strength of their gaze; while the eaglet, which turns away its eye from the sun's ray, is expelled from the nest as a degenerate creature!

So true is it, therefore, than to one eye an object is invisible, which may be quite plainly seen by another—without implying any incorporeality in that which is not endued with an equally strong power (of vision). The sun is indeed a bodily substance, because it is (composed of) fire; the object, however, which the eaglet at once admits the existence of, the owl denies, without any prejudice, nevertheless, to the testimony of the eagle. There is the selfsame difference in respect of the soul's corporeality, which is (perhaps) invisible to the flesh, but perfectly visible to the spirit. Thus John, being “in the Spirit” of God, beheld plainly the souls of the martyrs.