ABSTRACT
This chapter shows how Aristotle was able to arrive at his views through a criticism of his predecessors' erroneous use of contrariety. It aims to state the conceptual apparatus which Aristotle used in his reconstruction of the principle of contrariety in terms of the historical antecedents of his ontological approach. The chapter also aims to draw the lines that distinguish Aristotle's analysis from Plato's dialectic treatment of contraries and to indicate wherein the fault of the latter lies. It provides an exposition of all the varieties and ramifications of the cosmological use of contrariety in the pre-Socratic philosophies, all of which had in one way or another hypostatized it and used it as a material cause. The chapter focuses on the basis of a theory of contrary elements, Aristotle's stoichiology with the pre-Socratic ones, and to indicate in the light of contrariety the merits and shortcomings of his qualitative 'chemistry'.
