Leonardo's musings about romance, and about human qualities, behavior, and failings, appear to have led to his unusual drawing of Phyllis Astride Aristotle (c. 1475–78), a scene of such awkward folly that it anticipates the antiheroics of Shakespeare and Rembrandt (fig. 17). The specific impetus for the study was probably either a contemporary Florentine engraving or one of many circulating Northern European prints of the subject. According to legend, the ancient Greek philosopher Aristotle, of steely mind but evidently weak knees, allowed his beautiful young mistress, Phyllis, to ride on his back in exchange for her favors.

In a cramped sketch of ungainly postures and forced perspective (the furniture recedes too rapidly in space), Leonardo gently pokes fun at his supreme intellectual mentor, who, on all fours, looks back imploringly and shamefully at his dominatrix, in the general direction of the bed that awaits them. For the good-humored Leonardo the contrast between the realms of the intellect and the flesh made for fine parody – a telling counterpoint to Michelangelo's self-flaying paintings and poems devoted to related themes of base carnality. Leonardo's bemused attitude toward heterosexual conduct is apparent in a remark he later jotted in one of his notebooks: “the act of procreation and everything that has any relation to it is so disgusting that human beings would soon die out if there were no pretty faces and sensuous dispositions.”