Abstract

In chapter VII of On Interpretation, Aristotle alters a system of three pairs of natural contradictory propositions, in that he ignores the pair where two natural universals Men are white, Men are not white oppose each other contradictorily. This alteration has serious consequences: the two natural pairs, which Aristotle considers exclusively: All men are white versus Some men are not white and Some men are white versus No man is white are illegitimately identified to the two pairs of logical contradictories constituting the logical square: A versus 0 and I versus E respectively. Thus, the level of natural language and that of logic are confused. The unfortunate Aristotelian alteration is concealed by the translation of propositions known as indeterminates. To translate these, which, semantically, are particulars, all scholars, except for P.Gohlke, employ the two natural universals excluded by the master! The work of I. Pollak, published in Leipzig in 1913, reveals the origin of this nearly universal translation mistake: the Arabic version upon which AI-Farabi unfortunately bases his comment. In adding the vertices Y and U to the four ones of the square, the logical hexagon of Robert Blanche allows for the understanding of the manner in which the logical system and the natural system are linked.