Hume:The sun has risen in the east everyday in the past, but there is no way to know for sure that it will rise in the east tomorrow
Descartes:The sun might not be real, tomorrow might not be real. I am real. God is real. That's it.
Kant:You will probably perceive the sun as rising in the east tomorrow because that is what your preset knowledge tells you will happen, but "tomorrow" and "the east" are concepts that don't exist without human perception.
If you still have Cartesian-style doubts about how the physical could interact with the mental, then I suggest you buy a physical bottle of scotch, pour it down your physical throat, and wait to see if any mental changes take place.
René Descartes studied anatomy and physiology, as well as philosophy. But his “Treatise of Man” went unpublished during his lifetime, since he feared condemnation by the Inquisition. It was published in Latin after his death as “De Homine” (On Man). This woodcut of the nervous system is from a rare early copy of that book.