 Diderot’s monumental article “Beau” of the Encyclopédie contains one of the best summaries of French aesthetic thought in the eighteenth century, as well as some new ideas for artistic judgment. Early in the article, he exposes the circular reasoning inherent to theories of beauty: according to Saint Augustine, unity is the defining characteristic of beauty—a symmetrical building would be an example. “But why is symmetry necessary?” asks Diderot, who answers himself, “Because it pleases”. “Why does it please?” he continues, “Because it is beautiful”. “Why is it beautiful? Because it is unified”. Unable to resolve this problem, he then goes on to summarize the theories of beauty by André and Crousaz, as well as by Hutcheson and German philosopher Christian Wolff. While Diderot claims to consider André’s treatise the most profound and coherent, he still objects to the necessity of innate ideas about what is beautiful. Instead, Diderot argues that all conceptions of symmetry, proportion, and beauty come from our observations.