Full Idea
I am in ignorance whether the pineal gland can be agitated more slowly or more quickly by the mind than by the animal spirits.
Gist of Idea
Can the pineal gland be moved more slowly or quickly by the mind than by animal spirits?
Source
comment on René Descartes (Meditations [1641], §6.82) by Baruch de Spinoza - The Ethics V Pref
Book Reference
Spinoza,Benedict de: 'Ethics, Improvement of Understanding, Letters', ed/tr. Elwes,R [Dover 1955], p.246
A Reaction
Is this the earliest statement of the problem of double causation? It is a classic difficulty for dualists, highlighted by Ryle, among others. Avoidance of double causation is a classic reason for moving to monism about mind.