The idea of an immaterial soul is easy to imagine; however, it’s difficult to reconcile with neuroscientific evidence. Descartes never got to wander a neurology ward. If he had, he would have seen that when brains change, people’s personalities change. Some kinds of brain damage make people depressed. Other changes make them manic. Others adjust a person’s religiosity, sense of humor, or appetite for gambling. Others make a person indecisive, delusional, or aggressive. Hence the difficulty in the framework that the mental is separable from the physical.
