“Mental illness is caused by a chemical imbalance in the brain which can be treated by pills that correct this imbalance.”
This is the most prevalent view of mental illness, and the reason why almost every psychiatrist will prescribe drugs on the first day people approach them for help.
At its core, this view arises from a philosophical argument that behaviors, experiences, emotions arise purely from the brain—that material, physical, gray lump inside our skulls.
This argument is an argument about “what exists.” It is a metaphysical argument.
But to assert that everything that exists are physical in nature misses the fact that an outside observer can see another person’s.