Mechanical man

Descartes is accused of proposing that the human soul is a “ghost in the machine.”

Does he think of the body mechanistically? It’s true that he speaks of “our body’s machine” that operates in large measure “unaided” ( The Passions of the Soul: An English Translation of Les Passions De L’Ame , sections 7, 17). Yet he no sooner explains digestion and the circulation of the blood and other bodily functions than he introduces the category of “animal spirits” ( les esprits animaux , section 8).

It would be a mistake to think that Descartes goes occult. The animal spirits run through the nerves like a “very fine air or wind” through a tube, and they are not “spectral” in the least: “They are merely bodies, like any other bodies except for being extremely small and moving very fast, like flames shooting from a bonfire” (section 10).

It seems that the charge sticks: the body is matter and all its operations occur by “unaided” mechanical processes.