erection, or boiling an ass's genitals in oil as an ointment. Theories of sexuality Ancient theories of sexuality were produced by and for an educated elite. The extent to which theorizing about sex actually affected behavior is debatable, even among those who were attentive to the philosophical and medical writings that presented such views. This elite discourse, while often deliberately critical of common or typical behaviors, at the same time cannot be assumed to exclude values broadly held within the society. Epicurean sexuality The fourth book of Lucretius' De rerum natura provides one of the most extended passages on human sexuality in Latin literature. Yeats, describing the translation by Dryden, called it "the finest description of sexual intercourse ever written." Lucretius was the contemporary of Catullus and Cicero in the mid-1st century BC. His didactic poem De rerum natura is a presentation of Epicurean philosophy within the Ennian tradition of Latin poetry. Epicureanism is both materialist and hedonic. The highest good is pleasure, defined as the absence of physical pain and emotional distress. The Epicurean seeks to gratify his desires with the least expenditure of passion and effort. Desires are ranked as those that are both natural and necessary, such as hunger and thirst; those that are natural but unnecessary, such as sex; and those that are neither natural nor necessary, including the desire to rule over others and glorify oneself. It is within this context that Lucretius presents his analysis of love and sexual desire, which counters the erotic ethos of Catullus and influenced the love poets of the Augustan period. Lucretius treats male desire, female sexual pleasure, heredity, and infertility as aspects of sexual physiology. In the Epicurean view, sexuality arises from impersonal physical causes without divine or supernatural influence. The onset of physical maturity generates semen, and wet dreams occur as the sexual instinct develops. Sense perception, specifically the sight of a beautiful body, provokes the movement of semen into the genitals and toward the object of desire. The engorgement of the genitals creates an urge to ejaculate, coupled with the anticipation of pleasure. The body's response to physical attractiveness is automatic, and neither the character of the person desired nor one's own choice is a factor. With a combination of scientific detachment and ironic humor, Lucretius treats the human sex drive as muta cupido, "dumb desire", comparing the physiological response of ejaculation to the blood spurting