Praxeology is the conceptual theory of the science of human action, that is non-instinctive action. It identifies one axiom out of which all subsequent concepts are derived: Human action chooses certain ends and, after consciously comparing the different means available, chooses out of those available means in order to attain these ends.

Praxeology examines the objectives aimed at and the means employed in order to attain these objectives. It explains the causes and effects of human action. It does not explain the thought process that leads to the decision of pursuing a certain aim (psychology). Nor does it question the morality of the actor's ends (ethics). It merely examines whether the means employed are fit to attain the end sought.

Every human action is an act of exchange. At any given point in time, the actor trades one state of affairs for a different one. This is the driving force of all human action.

The axiom that human action aims at objectives and is performed in order to attain these is irrefutable. If one were to set out to refute its correctness he himself would be aiming at an objective and choose actions that he sees fit to attain this objective.