The significance of "De inventione dialectica" for the history of argumentation is that it assimilated the art of dialectic to that of rhetoric. Argumentation focused not on truth but on what might be said with reason. Accordingly, Agricola focused on the "Topics" rather than the "Analytics" of Aristotle and on Cicero, but also on the writings of historians, poets, and orators. Thus, for Agricola, dialectic was an open field; the art of finding "whatever can be said with any degree of probability on any subject." (Hamilton, David. "From Dialectic to Didactic").