Theodore Dreiser published over fifty items of literary criticism between 1900 and 1945 on a wide variety of subjects, while additional discussion of literary matters is scattered through his correspondence, memoirs, unpublished speeches, and cultural and philosophical essays. Hitherto this work has proved useful piecemeal, in its illumination of Dreiser’s fiction, while a few outstanding pieces have served to define Dreiser’s version of realism or literary naturalism. This essay takes the literary criticism seriously as a body of work in itself, sketching out some categories and topics, and providing detailed historical contexts for several items, which reveal under-appreciated nuances and engagements in even better-known pieces such as “True Art speaks Plainly” and “Life, Art and America.” The essay sees coherence across the diverse foci of Dreiser’s literary criticism via the concept of the “occasions of literary criticism,” by which is meant the historical and cultural contexts into which he was writing. It charts the roots of Dreiser’s literary criticism in his need to respond to charges of “literary immorality,” its growth through his very particular response to censorship, and its maturity in his suggestion, in a speech given as part of the peace conference in Paris in 1938, of an American literary tradition dedicated to social justice, taking in Mark Twain and H. D. Thoreau as well as the expected cohort of realists and naturalists. The essay concludes by relating these contexts and preoccupations to the history and practice of the Theodore Dreiser Edition.