study of body, mind, and soul?

i know the study of the body is called physiology, and the study of mind is called psychology, the study of the soul however i do not know it’s name. i previously thought either theology or philosophy possibly, but neither of those are quite what i thought, theology being the study of God,and philosophy being the study of soul, mind, and other aspects of humanity and existence. so if there is a distinct study of soul, what is it called, and if not, what field of science or research most closely defines the soul. please and thank you for answers.