The term of prohairesis was systematically entered in philosophical debates by Aristotle. This concept is generally translated as intention, will, purpose, choice, purposive choice, rational choice, and deliberative choice that the later seems to be Aristotle's definition of prohairesis. To understand the internal structure of prohairesiss, we have to understand the conceptions of action, intention, belief, whish, will, and virtues. For Aristotle if an action will be done through a decision, this action is voluntary, but its contrary is not credible. He believes that the children and animals act voluntarily, but they have not any decision, because they have not any deliberation.