Dreiser's friendships with literary figures mirror the variable elements of his temperament—that is, his capacity for sympathetic engagement with others attracted close relationships, while his “irascible” and “loutist” phases (as noted by Edgar Lee Masters and H. L. Mencken) often caused long interruptions or permanent breaks in such relationships.

Among his friendships, only those with Richard Duffy, John Cowper Powys, and William C. Lengel lasted the course of Dreiser's lifetime, perhaps because he seldom saw Duffy after 1904, because he and Powys met only sporadically, and because Lengel was more an acolyte than personally close. His relationships with Arthur Henry, H. L. Mencken, Edgar Lee Masters, and Otto Kyllmann (his editor at Constable, his English publisher) are more characteristic of the “failed romance” pattern of many of his friendships. An initial period of intense engagement is followed by a quarrel or disagreement that causes either a complete break or a lengthy separation and a tepid renewal of the relationship. (In Masters’ case, however, the friendship was renewed with full force after a long lapse.)

Richard Duffy

“When They Were Twenty One”

Another man who was writing some verse at this time and who was writing a good deal more prose in the form of illustrated articles for the magazines, but whose later work has placed him as a serious novelist, is Theodore Dreiser. But Sister Carrie was being thought out, and when once he really got down to writing it the fecundity of the man was amazing. Every few days he could make the breezy announcement that since he last came in view he had written as many as ten or twenty thousand words. When the book was ready for the printer, if memory is correct, he had written half again as much on the story as is published. Although some critics have likened the model of his novels to that of Zola, the master Dreiser recognised and venerated was Thomas Hardy; and while he was working on Sister Carrie, in fact before he set out, his outline of the story's backbone, showing his characters moving to an inevitable fate, suggested the Hardy method.