In "The Art of Theater," the author proposes and explains a claim that many theater people hold true in some form but have defended in a manner that has had almost no success outside discussions among themselves. The claim proposed is that, in an unqualified way, theater is a form of art. By that the author means theatrical performances are "what are created" in the practice of theater and that theatrical performances are "works of art" because they can be picked out and appreciated in the same ways one appreciates other kinds of artworks. In this article, the author explains and clarifies this claim and many other arguments presented in the book. (Contains 18 notes.)