Praxeology is the science of human action. The term was coined and defined as "The science of human action" in 1890 by Alfred Espinas in the Revue Philosophique, but the most common use of the term is in connection with the work of Ludwig von Mises and the Austrian School of economics.
 Purposefulness of action
Praxeology is the scientific study of human action, which is purposeful behavior. A human acts whenever he uses means to achieve an end that he or she subjectively values. Human action is thus teleological or intentional; a person acts for a reason. Therefore not all human behavior is action in the praxeological sense: purely reflexive or unconscious bodily movements (such as coughing when exposed to tear gas) are not examples of action. Praxeology starts from the undeniable axiom that human beings exist and act, and then logically deduces implications of this fact. These deduced propositions are true a priori; there is no need to test them in the way that a physicist might test a proposed "law" of Nature. So long as a praxeological statement has been derived correctly, it must necessarily contain as much truth as the original axioms.
For example, when we throw a ball, we do not reason that it is guided in a teleological way by some mystical spirit or "prime mover." Instead we use the laws of mechanics and causality to examine the position, velocity, and forces acting on the ball, in order to predict the future position and velocity of the ball.
On the other hand, one does not reason that there is some sort of direct, causal relation between traffic lights turning green, and bodies beginning to cross the road. These are individuals acting with purpose crossing the road, who, only when the lights turn green, reason that it is safe to cross and then proceed to do so. The reckless individual who is late for work may rush across the road regardless of what the traffic lights show.
- A. The Theory of the Isolated Individual (Crusoe Economics)
- B. The Theory of Voluntary Interpersonal Exchange (Catallactics, or the Economics of the Market)
- C. The Theory of War--Hostile Action
- D. The Theory of Games (e.g., von Neumann and Morgenstern)
- E. Unknown
- Robert P. Murphy "A Study Guide to Murray Rothbard's Man, Economy, and State, with Power and Market", online version, referenced 2009-06-15.
- Abhinandan Mallick. "How I Found the Austrian School", Mises Daily, posted on 2009-10-09, referenced 2009-10-10.
- Murray N. Rothbard. "Praxeology: Reply to Mr. Schuller", American Economic Review, December 1951, pp. 943-46, referenced 2009-05-20.
- Praxeology.tv Educational resources
- What the Hell is Praxeology? on Praxeology.net
- Praxeology: The Methodology of Austrian Economics (PDF) by Murray N. Rothbard
- Praxeology at Wikipedia