The relation of contrariety in the ancient thought and in the Aristotelian formalization

In the Greek language two words are used to indicate opposite things: antikeimenos and enantios. Grammatically the word antikeimenos is a middle passive present participle deriving from antikeimenai. In turn, this verb is made up of the preposition anti (which acts as a prefix) and from the verb keimai. The preposition anti has several meanings and different nuances however it essentially carries three concepts: the meaning of 1. being “in front of”, “face to face” (in this case it corresponds to the Latin ante); 2. “instead of”, “in place of”; 3. “in change of”, “rather than”. In Aristotle’s physical works, a number of very interesting applications of some models of contrariety can be found especially from the perceptive point of view. In these works, it is evident that the organization of reality based on contrariety expresses a requirement of classification and order which, in most cases, Aristotle takes out starting from a strong attention to the experience. Moreover, through these examples it is possible to verify the different functionalities that contrariety can assume with respect to the classification or explanation of reality.