Monroe C. Beardsley's "Aesthetics: Problems in the Philosophy of Criticism," published in 1958 by Harcourt, Brace and World Inc., was a watershed event in the history of analytic aesthetics--a climax of sorts with respect to what preceded it and, at the same time, the opening of a new, more intricately developed and defended research program in aesthetics than what had been previously on offer. Beardsley's "Aesthetics," and developments therefrom, consolidated and crystallized a tendency in aesthetics that had begun to emerge at least by the time of the publication of Francis Hutcheson's "An Inquiry Concerning Beauty, Order, Harmony, Design," which tendency, following Beardsley, one can call the aesthetic theory of art. In this article, the author traces the evolution of the aesthetic theory of art from its origins through to Beardsley's "Aesthetics" (and his subsequent tinkering with this masterwork) and shows how the structure of the aesthetic theory of art, as crafted by Beardsley, is simultaneously so elegant, comprehensive, and systematic. The author addresses the shortcomings of the aesthetic theory of art, and talks about its strengths that encouraged Monroe Beardsley to stick with it. Then, the author tries to place "Aesthetics" historically in the course of Western aesthetics. Finally, the author attempts to explain how the structure of the sort of aesthetic theory of art incipient in Beardsley's "Aesthetics." (Contains 11 notes.)