Aristotle employs systems thinking to elucidate the nature of body and soul and the relationship between individuals and State (Russell, B., 1961, History of Western Philosophy, George Allen and Unwin, London.). Just as a hand can only fulfill its purpose, of grasping, when joined to a body, so an individual must be a part of a State in order to fulfill his purpose. In Aristotle's philosophy the whole is clearly prior the parts and the parts only obtain their meaning in terms of the purpose of the whole - they are not separable.