Early Modern Philosophy
What was Princess Elizabeth’s philosophical influence on René Descartes?
Descartes wrote Passions of Soul mainly to try to answer her questions about how the mind interacted with the body.
In that book, Descartes discusses how emotions are the mind’s perceptions of disturbances in our bodies. He thought that the will was part of the soul and immaterial but that there were very delicate fluids in the pineal gland that the will could influence. The result was that parts of the body could be controlled by the mind.