Department of Educational Psychology


Document Type


Date of this Version



Cognitive Development 26:3 (July–September 2011), pp. 192–195.

doi: 10.1016/j.cogdev.2011.03.002


Copyright © 2011 Elsevier Inc. Used by permission.


For anyone who loves a strong major thesis—and I do—Mercier’s “Reasoning serves argumentation in children” [this issue] obliges right from the title. And for anyone who loves a carefully structured defense of a provocative perspective—and who does not?—Mercier’s article continues to fill the bill.

The “argumentative theory of reasoning” maintains that “reasoning is a fundamentally social ability” that “has evolved to serve argumentive ends: finding and evaluating arguments in a dialogic context.” There appear to be two distinguishable theses here: first, reasoning serves argumentive ends; second, reasoning has evolved. In their moderate versions, each thesis is true and useful; their stronger versions, however, are questionable and misleading. Reasoning is both social and individual, with roots in the human genome, sensorimotor action, and subsequent individual and social coordinations and reflections. Thus reasoning serves argumentive purposes among others, and what evolves is a tendency toward developmental processes that, in supportive environments, generate progress in reasoning and argumentation.