Imagery appears frequently in Allen’s writing, especially as he crafts the extended similes that make his ideas more understandable to a general audience. Allen is also a poet, and one of his poems appears at the end of the second section, “Effect of Thought on Circumstances.” Imagery is a popular literary device in both poetry and prose, and Allen uses vibrant images to immerse readers in the text’s ideas and increase his argument’s emotional impact. In the early lines of the first section, “Thought and Character,” Allen explains his central idea through imagery: “As the plant springs from, and could not be without, the seed, so every act of a man springs from the hidden seeds of thought, and could not have appeared without them” (7). Allen invites readers to picture a natural phenomenon of plants growing and then relates the image to his thesis that people’s actions and characters result from their thoughts, making the notion more perceptible by comparing it to a well-understood occurrence in nature.

Allen uses imagery often in the final section of the text, “Serenity.” In the final paragraph, he writes, “Tempest-tossed souls, wherever ye may be, under whatsoever conditions ye may live, know this in the ocean of life the isles of Blessedness are smiling, and the sunny shore of your ideal awaits your coming” (47). In this passage, Allen constructs an image of a person sailing toward an idyllic island to describe a person obtaining their vision and becoming their ideal. This imagery creates an encouraging, warm tone to inspire readers to pursue their goals and purpose.

Simile, which compares two unlike things, often using “like” or “as,” is a literary device that Allen uses throughout As a Man Thinketh to liken a person’s mind to a garden. He introduces this simile in the first section, “Thought and Character,” and expands on it in the second section, “Effect of Thought on Circumstances”:

Man’s mind may be likened to a garden, which may be intelligently cultivated or allowed to run wild; but whether cultivated or neglected, it must, and will, bring forth. If no useful seeds are put into it, then an abundance of useless weed-seeds will fall therein (11).

Allen uses the garden simile in tandem with imagery to help readers understand his ideas, using a palpable scenario to illustrate a highly theoretical concept. This simile grounds his philosophical ideals in physical, concrete examples from the natural world and thus helps guide readers on their journey toward self-improvement. In another simile, he writes, “Only by much searching and mining, are gold and diamonds obtained, and man can find every truth connected with his being, if he will dig deep into the mine of his soul” (10). Allen wants people to learn to connect with their innermost selves, and instead of simply stating that, he makes his message sink in by conjuring a visceral image for readers to connect with.