Psychology has a bad name in libertarian circles. Read for example on lewrockwell.com. Robert Murphy argues that there is a dividing line between psychology and praxeology. The root of these opinions is Mises who was not fond of „experimental psychology”. However he sees psychology or “literary psychology” in the realm of thymology yet not in the realm of praxeology. He states:
I argue that rational psychology is not literary or thymological in its nature, it’s fully praxeological. Psychological causes of purposeful human behaviour are also purposeful. I like to think it is one of Rothbard’s yet unknown categories of praxeology.
Psychological Causes of Human Action
Mises uses the following terms for what is going in human mind and for what is the cause of action: "psychological events", "psycho-analytical subconscious", "[psychological] forces and factors".
Similarly, Hoppe talks about "motives and reasons" as causes of “events". He says:
Following Tadeusz Kotarbiński I use the term "internal actions" for conscious and unconscious motives and reasoning or human thoughts and emotions, which precede and which cause Misesian external actions.
Definition of Psychology
An argument is an action in itself. You argue with others but you also argue with yourself. Your external actions are caused by your internal argumentation. Your conscious or unconscious mind persuades you to certain actions. This is what I call psychology – argumentation or relation with oneself. And if argumentation with others is a praxeological category and is subject to logical-axiomatic approach so has to be the argumentation with oneself, i.e. internal actions that take place in our conscious and unconscious mind.
True Content of Psychology
The logical presupposition for human action and argumentation is the non-aggression principle. We can mirror that principle onto the internal actions and argumentations. If a theory of human relations which embraces the non-aggression principle is the only way to understand human relations the very same theory is the only way to understand what is going on in human mind, the very cause of those relations. The true content of psychology is thus understanding why an individual aggresses against his/her very self, and finding and eliminating sources of that aggression in order to live a spontaneous happy life.
Branches or Categories of Psychology
The Theory of Self-Aggression: why I aggress against myself (including the body), why I accuse myself, why I do not love myself, why I do not take care of myself, what are the effects of that aggression, where are the sources of my aggression.
The Theory of Self-Healing, Therapy: how to eliminate self-aggression.
The Theory of Self-Conversation, Negotiations with Oneself: how to exchange ideas between our different egos, or personalities.
The Theory of Self-Ethics: the theory of preferable behaviours/thoughts toward oneself; what constitutes a happy life.