The purpose of this study is to examine the parallels between the tenets of Carl Jung's psychology and the mythopoeic structure of Blake's poem, The Four Zoas. The investigation is divided into three chapters. The first deals with the major conceptual parallels between the intellectual systems of the two men. The second is a detailed analysis of the poem, and the third concludes the study by discussing the originality of Blake's thought. Blake anticipated much of Jung's psychology. The parallels between the two are so strong that each man seems to corroborate and validate the opinions and insights of the other. The extent to which he foreshadows Jung reveals Blake to be one of the most original thinkers of any period of time.