Tertullian, A Treatise on the Soul 6

The Platonists muddle these matters with cleverness rather than truth. They insist every body must be either animate or inanimate. If it's inanimate, it gets moved from outside; if animate, from within. But the soul fits neither: it isn't moved from within, since it's not inanimate, nor from outside, since it's the very thing that moves the body. So it doesn't look like a body at all—one that isn't shifted by corporeal forms from some quarter. We're left gaping at the first incoherence: a definition that drags in categories that simply don't apply to the soul. The soul can't be called an animate body or an inanimate one, because it's the cause: it makes a body animate when present, inanimate when absent. What produces a condition can't itself be that condition. The soul bears the name of its own substance. If something that isn't a body can't be labeled animate or inanimate, how can it be forced into the mold of animate and inanimate bodies?

Next: if being moved from outside by something else is a mark of a body, then we've already shown the soul is moved by another—when it prophesies, when it raves—certainly from outside, by another. So by the very logic of the example, I'd have to call the soul a body. But if being moved by another is a body's trait, moving another is even more so. And the soul moves the body; its impulses show themselves outwardly. It's from the soul that feet are driven to walk, hands to touch, eyes to see, tongue to speak—as a seal impresses a surface by a motion working from inside. Where does an incorporeal soul get this force? How does a void shove solid things?

But how, they ask, do senses split in us into bodily and intellectual? Bodily qualities—earth, fire—are reported by bodily senses: touch, sight. Incorporeal qualities—kindness, malice—belong to intellectual senses. Therefore, they conclude, the soul is incorporeal, since its qualities are grasped not by bodily but by intellectual senses. That is, if I haven't already knocked out that step of the definition. Watch: I show incorporeal things submitting to bodily senses—sound to hearing, color to sight, odor to smell. By that same pattern the soul, too, approaches the body; don't claim it's reported by bodily senses just because it draws near bodily things. So if incorporeal things can be grasped by bodily ones, why can't a bodily soul be reported by incorporeal ones? The definition is sunk.

Another flagship argument: every body is judged by bodily things; the soul, as incorporeal, by incorporeal ones—namely, the pursuit of wisdom. But this rung won't hold either. Even Soranus, the most accomplished author of methodical medicine, answers that the soul is also fed by bodily things; in fact, when it's failing, it's usually propped up by food. Take the food away and it slips out of the body altogether. Soranus himself, after commenting on the soul in four volumes and testing every philosopher's opinion, defends the soul's corporeal substance—though he cheats it of immortality. Not everyone believes what Christians believe. So just as Soranus demonstrates the soul is nourished by bodily things, let the philosopher demonstrate it's fed by incorporeal ones. No one has ever poured honeyed water from Plato's discourse into a hesitating soul, or sprinkled dust from Aristotle's minutiae. What will all those countless souls of peasants and barbarians do—who lack wisdom's nourishment yet thrive on untaught prudence, with no academies, no Attic porticoes, no Socratic prisons, fasting from philosophy, and still live? It's not the substance's nourishment that advances learning, but the disciplines; they don't make the soul richer, only more polished.

And well done: the Stoics, too, declare the arts are bodily. So the soul is bodily as well, if it's thought to be fed by the arts. But philosophy's huge ambition usually can't see past its own feet—like Thales falling down a well. It also suspects sickness when it fails to understand opinions—like Chrysippus turning to hellebore. Something like that, I suspect, happened when it denied two bodies can occupy one space, having lost sight and memory of pregnant women, who don't just carry single bodies day by day but two or three within one womb. Roman law even records a Greek woman bearing five children at once—once mother of all, parent of a single fetus, mother of many, packed with so many bodies she was practically a people, herself the sixth body. The whole order of nature testifies: bodies come from bodies, right there where they originate. What comes from another must be second; nothing comes from another except in being born—and then there are two.