Perceiving, then, is like mere utterance and thought; but when something is pleasant or painful, [sc. the soul] pursues or avoids it, as it were affirming or denying it; (2) and the pleasure and pain in question are activities of the soul with the perceptual mean in relation to the good or bad as such. And this is also what the actual avoidance and desire in question are;
— Hendrik Lorenz
Aristotle is doing something subtle here that the Platonic inheritance tends to flatten. Perception, for him, is not passive registration — it is already evaluative, already oriented. When the soul encounters something pleasant or painful, it does not first perceive neutrally and then decide; the pleasure and the pain *are* the soul's first words about value. The affirming and denying happen in the body before the reasoning mind has assembled its case.
What this means is that desire and avoidance are not failures of reason. They are the soul's primary grammar — the perceptual mean in contact with the good or bad as such. Aristotle is insisting that appetite carries genuine cognitive content, that wanting something is already a kind of knowing, already a report on what the world is like from where the soul stands in it.
The pneumatic tradition has spent two millennia convincing us otherwise — that desire distorts, that the body misleads, that the path to clear sight runs through detachment from precisely this perceptual-appetitive fabric. Aristotle refuses. What avoids and pursues is not the noise beneath cognition; it is cognition in its most immediate register. To bypass it in the name of clarity is not to see more truly. It is to go deaf in the place where the soul is still speaking plainly.
Hendrik Lorenz·The Brute Within: Appetitive Desire in Plato and Aristotle·2006