What is the difference between philosophy (we did have natural philosophy) and psychology (now we even have neuroscience)?
Philosophy deals with questions of value, aesthetics, and logic. (the good, the beautiful, and the true).
Psychology, which was once a branch of philosophy but has become a separate science (philosophy is also known as the queen of the sciences) deals with the nature of the psyche (or soul) in empirical terms. The key word now is empirical, e.g. cognitive and behavioral approaches dominate the field these days.