Alfred Adler states that "The supreme law of life is this: The sense of worth shall not be allowed to be diminished." His view supports a central theme in Boss Canvasman. The setting involves the O'Donnell family and ex-circus workers during the 1930s, a time of the Great Depression and Prohibition in the United States. Devlin O'Donnell strives for a sense of well-being only to experience painful shame through the bizarre behavior of his brother, Egan. As Devlin seeks the love of Eileen Coleman, he fears Egan's mannerisms will convince Eileen that Devlin is also mentally unbalanced. Throughout the narrative, he struggles to deny this interpretation. Egan's closeness to his mother, Maura, adds mystery to the novel. Determined to uncover its meaning, Devlin engages in a search that brings him to a secret Egan shares with Maura. At a pivotal point in the tale, the mystery unfolds, and Devlin explodes in drastic action. The ex-circus people provide further structure to the narrative. Jerry Burke is a former boss canvasman, the person responsible for erection of the main tent. Sean Sweeny who had unloaded flatcars befriends Devlin. Sean's ambiguous references to the boss canvasman puzzle Devlin, adding intrigue to the story. Injured in a circus accident, Sean longs for a return to the circus, a life maintaining his self-esteem. Sean's use of Irish lore and circus language bind the novel together metaphorically. His desire for recognition creates disturbing consequences for himself and Devlin.