The middle term between dialectic and being is definition. Definitions are formulae of essences or substances. Thus, one’s view of substance will depend on one’s view of definition: what a definition is, and how it is acquired. Further, insofar as definitions are arrived at through dialectic, definitions depend on dialectic. That is, the specific procedure of dialectic shapes the mode of definition, and the mode of definition shapes the notion of being. Not only does dialectic shape being through definition, but being and knowledge of it also determines dialectic. In short, these three things go together: dialectic, definition and being. My task is to explore this nexus and reveal the essence of Aristotle’s philosophical dialectic.
Sim, May, "Dialectic and Definition in Aristotle's Topics" (1995). The Society for Ancient Greek Philosophy Newsletter. 326.