Mendelssohn never presented his aesthetic theory in a full-length treatise. His most systematic presentation, the 1757 essay “On the Main Principles of the Fine Arts and Sciences,” discusses only three out of the four axes of potential perfection that he finds in the complete aesthetic experience. We therefore need to supplement what we can glean from this essay with suggestions from On Sentiments and the Rhapsody, or addition to the Letters on Sentiments that he added to his 1761 collection. Th