Meditation 2 — Of the Nature of the Human Mind

The First Meditation left Descartes disconcerted — unable to plant his feet on the bottom of the doubt or to swim to the surface. Now he supposes everything he sees is false, that he has no senses, that body, shape, and extension are fictions of his mind. And then he notices something. Even if all this is false, something must be doing the supposing. He cannot be non-existent if there is a deceiver deceiving him — being deceived requires existing to be deceived. I think, therefore I am. This one fact the evil deceiver cannot falsify.

What, then, is he? Not a body — the existence of bodies is still in doubt. He is a thinking thing: something that doubts, understands, affirms, denies, wills, refuses, imagines, perceives. These are the modes of thought, and they cannot be separated from him the way bodily properties can. Even if he imagines nothing and perceives nothing true, the doubting and the willing are still there. The thinking self is real and better known than anything else.

The wax example follows and deepens the point. A piece of wax, fresh from the hive, has a particular scent, color, shape, and hardness. Held near the fire, every sensible quality changes — and yet Descartes judges it to be the same wax. What persists is not anything the senses report but something extended, flexible, and changeable — a bare physical extension. This extended something is grasped not by the senses or the imagination but by the intellect alone. And if bodies are better known through the intellect than through the senses, then the mind — which is the intellect — is more immediately known than any body. The Second Meditation ends at the threshold of a rebuilt world, with the thinking self as its foundation.