Descartes, René (1596-1650)

Principles of Philosophy

Amsterdam

Elzevir

1644, 1647

"Sensory awareness comes about by means of nerves, which stretch like threads from the brain to all the limbs, and are joined together in such a way that hardly any part of the human body can be touched without producing movement in several of the nerve-ends that are scattered around in that area"

It must be realized that the human soul, while informing the entire body, nevertheless has its principal seat in the brain; it is here alone that the soul not only understands and imagines but also has sensory awareness. Sensory awareness comes about by means of nerves, which stretch like threads from the brain to all the limbs, and are joined together in such a way that hardly any part of the human body can be touched without producing movement in several of the nerve-ends that are scattered around in that area. This movement is then transmitted to the other ends of the nerves which are all grouped together in the brain around the seat of the soul, as I explained very fully in Chapter Four of the Optics.†1 The result of these movements being set up in the brain by the nerves is that the soul or mind that is closely joined to the brain is affected in various ways, corresponding to the various different sorts of movements. And the various different states of mind, or thoughts, which are the immediate result of these movements are called sensory perceptions, or in ordinary speech, sensations.
(Part Four, p. 279-80)

Fabric::Threads

Past Masters

Descartes, René, The Philosophical Writings of Descartes. trans. John Cottingham, Robert Stoothof, and Dugald Murdoch (Cambridge: Cambridge University Press, 1985).

10/03/2003

12/03/2008