Isaac Bashevis Singer's work has often been identified with demons, but his use of the Yeytser-hore as narrator may be more than a simple preoccupation with the realm of evil. Rather than merely portraying evil in literature, Singer was working within a mystical tradition that harnessed what it saw as the powers of evil to do good in the world. This aspect of Singer's work has been largely under discussed and underresearched. A fuller consideration involves delving into the sources of his inspiration—especially religious and kabbalistic works—to grasp not only the images or motifs he was pulling from but also the spiritual understandings that he found and applied to his literary practice. This article explores Singer's spiritual framework, discussing his use of demons in light of a handwritten note found in the Singer Papers in Austin, Texas. This note prompts an investigation into some of the ways in which his spiritual understandings influenced the themes, strategies, and images found in his stories.