In Aristotle’s Politics can be found many of the intrinsic and instrumental justifications of democracy that philosophers have subscribed since then in the last 24 centuries, despite the fact that Aristotle himself did not seem to be a big supporter of democracy. This article focuses on one of such justifications, the epistemic one, in the version he articulated as the so-called thesis of the «wisdom of crowds». Three elements of such thesis are identified: the aggregative element, the deliberative element, and the evaluative element. Regarding the scope of the thesis, the article refers to two different interpretations identified by Waldron, the Weak and the Strong ones, and adds a third one, half-way between those two. Finally, the article concludes by presenting the four main aggregative arguments —Bernoulli’s Theorem, the Condorcet Jury Theorem, the utilitarian argument, and the Hong, Page and Landemore’s Diversity Theorems—, and the main deliberative arguments, that mathematics, social epistemology and political philosophy literatures have given in favor of the thesis of the wisdom of crowds, since the time of Aristotle.