Humoral Theory and Sexual Health: Celibacy and Promiscuity as Medical Problems in the Medieval Age

A common misconception about medieval sex is that humans were prudish, they engaged in sexual intercourse for the sole purpose of procreation, and were strictly forbidden by church authorities from engaging in any sort of premarital sexual acts. Although these claims have merit, they fail to capture the nuances inherent in the sex practices of the medieval age, conflating sex with morality as dictated by established religion.

However, historical reductionism aside, sex was not always viewed as a moral issue. Physicians, learned medical men and many clerical figures, strongly influenced by the medical ideas of Galen and Hippocrates, often deviated from ecclesiastical decorum, prescribing sex and/or sexual acts as restorative remedies for the maintenance of bodily health. In fact, celibacy and excessive sexual activity were considered medical problems which could lead, in different ways, to humoral imbalances in the body and sickness. Sex transcended the religious realm into the medical, no longer bound to stigmatization nor the language of sinfulness. It was also a medical matter, carrying with it a host of health benefits and risks, an intellectual theory and a prescriptive methodology.

Thus, the aim of this paper is twofold: (1) to unearth the intellectual and practical connections between the Galenic-Hippocratic humoral theory and medieval sexuality, specifically in regards to celibacy and excessive sexual activity, and (2) to position this medicalized conception of sex within a long-standing debate between church and medical authorities, both supposedly vying for power to shape the cultural discourse. Ultimately, what is rendered is a new understanding of medieval sex — how sex aligned with the accepted theory of the four humors, how it affected individual health, and its dual nature as both remedy and ailment. But most importantly, evidence reveals how overstated the church/medical tension actually was since many Christians “did not rule out natural causes, for most medieval Christians shared the view, common since the Hippocratic writers, that an event or disease could be simultaneously natural and divine.” Sex for medicinal purposes was not always frowned upon and, in certain contexts, was actually sanctioned by church officials, painting a richer yet more complicated history of medieval sexuality.

Humoral theories of sex

Viewed through the medical ideas of Galen and Hippocrates, the medieval body was believed to be composed of four main humors, or fluids — black bile, yellow bile, phlegm and blood — all of which were “vehicles by which the proper balance of qualities is maintained.” Each humor corresponded to one of four elements and four qualities (cold, hot, dry and wet), a combination which formed an individual’s unique “temperament.” Thus, sickness and disease were the result of humoral imbalances in the body, the likes of which had to be remedied through restorative processes like diet, exercise and taking herbs/ointments. On the other hand, to be healthy was to be in balance, humors fully restored in equilibrium. The 13th-century “Salerno Regimen of Health” offers a glimpse into the common restorative practices that were prescribed to ill patients (and even to healthy ones as preventative measures):

Sleep not too long in mornings, early rise,
And with cool water wash both hands and eyes.
Walk gently forth, and stretch out every limb:
Comb head, rub teeth, and make them clean and trim.
The brain and every member else these do relieve,
And to all parts continual comfort give.
Bathing, keep warm; walk after food, or stand:
Complexions [that are] cold do gentle warmth command [require].

Remedies include lifestyle and dietary changes such as getting enough sleep, brushing one’s teeth regularly and exercising after meals. However, more interesting than the prescriptive measures outlined is that which isn’t: sexual activity. Wholly absent from this prescriptive poem is any mention of sex as a restorative antidote, or even harmful in scarcity or excess. Where sex factors into human longevity as determined by humoral health is nowhere to be found in these maxims, tailored to the masses. Although the non-historical instinct would be to overstate the author’s regimen as representative of an entire medical corpus, one must exercise caution when taking sex out of the medieval medicine conversation. The reality remains that there was much said about healthy/unhealthy sex by learned medical men.

Constantine the African, a monk whose writings were influenced by Galen’s Art of Medicine, did much to infuse sex into medieval health regimens. His treatise On Sexual Intercourse provides one of the earliest examples of an explicit connection between sex and medicine, “transforming sex into a medical issue, one that was explicable in physiological terms and susceptible to being discussed from a purely hygienic point of view.” Touching on the mechanics of sexual intercourse, who engages in it, how bodily fluids (semen) are expelled from the body, followed by prescriptive remedies for health conditions related to sex, he describes sex as the following:

There are, in fact, three things involved in sexual intercourse; appetite, which arises from fantasizing thoughts; spirit; and humor….[and] since there is a delightful motion in sexual intercourse, all the parts of the body are warmed through this motion, and the humor in the brain is liquefied by this warmth and when it is liquefied, it is drawn through the veins which are behind the ears and which lead down to the testicles and thence it is ejected by the penis into the vulva.

Sexual intercourse is not only delightful, but it warms the humors through ejaculation. “If it is cold and dry, there will be no appetite because of the cold and the semen will be scanty because of the dryness,” he adds. Both Aristotelian and Galenic-Hippocratic underpinnings are evident here, suggesting that Constantine was well-versed in the medical theories — namely, the humoral theory and even natural causes — of his time. Further, he describes sex from a primarily mechanical standpoint, avoiding any detailed discussion of its moral or religious implications, opting instead for a brief mention of thoughts and spirit without delving into them further.

It is evident in Constantine’s exposition that not only was sex conceptualized as something more than sin or a procreative tool (as dictated by morality and religion), but that it also played neatly into existing medical theories of disease. Like any remedy or curative, and as will be discussed in more detail in the following section, it had specific uses in treating humoral imbalances in the body depending on whether illness was a product of excess or deficiency as seen in the cases of celibacy and promiscuity.

Celibacy and Promiscuity as Medical Problems

On a scale of not enough (or none at all) sex or too much of it, celibacy and promiscuity (which I use to denote excessive sexual intercourse with one or many partners) are antithetical modes of being. To the medical observer, sex was a double-edged sword: have too much of it and the body is expelling too much semen; have too little and the body is not expelling enough. Regardless, the humors are not balanced and the key to maintaining a healthy humoral equilibrium was to have a “proper” amount of sex.

Celibacy and Sexual Abstinence

In a medical recipe directed towards clergymen and monks, Mauretanian abbott Gargilius Martialis (260 AD) states that the consumption of almonds is a means to “arouse sexual desire” in men, perhaps in reference to monks’ vows of sexual purity. Referencing Galen and Dioscorides, Martialis offers dietary advice (bordering aphrodisiac qualities) to abstinent monks in order to inflame their sexual desire. Because of the medical nature of the recipe, this reveals how as early as the 6th-century, increasing one’s libido was considered a health benefit to combat the cooling nature of celibacy, otherwise there would be no need to arouse a monk in the first place.

Perhaps more explicitly, the Salernian Articella medical compendium, in commentating on the ideas as outlined in the famous Isagoge, states that “sexual intercourse is beneficial for the body; it dries the body and diminishes the natural power and so cools it down, although oftentimes the body is warmed by a good deal of vigorous motion.” Sex functioned as a cure for the sexually repressed. Further, it is important to note two things: first, Martialis’ claim that sex warms the body of a monk is in direct contrast with the cooling description of sex in the Articella. Like many intellectual theories, humoral theory and how sex affected the humors (whether it was warming, cooling or both) was not a conclusive fact shared by all medical men, but was rather subjected to differing lines of interpretation depending on the context.

Secondly, although the above texts are written by and for men, the medicalization of sexual intercourse crossed gender lines, having extended into the realm of women’s health in obstetrics and gynecology. For pregnant women, virgins and widows — all of whom were not engaged in regular sexual intercourse — disease and pregnancy complications were linked to the abundance of female “seed” residing in their bodies “which Nature wishes to draw out by means of the male” through sex. Similar to Constantine’s recommendation that sex “should not be infrequent, because the warmth that is generated from the rapid motion of coitus condenses and dries,” women were also instructed to engage in sexual activity for the sake of their health. It was not a moral pronouncement as much as it was a medical intervention. For virgins and widows specifically, Joan Cadden writes, abstinence was viewed as particularly dangerous for women, so much so that physicians like Avicenna and Galen, some of the most learned medical authorities in medieval medicine, went as far as to prescribe masturbation for celibacy, recommending that women “rub the genitals until the seed is ejected.”

Historian Katherine Harvey confirms this practice, noting that for nuns who could not engage in procreative sexual intercourse (as virgins and widows might be able to), masturbation was one of a few outlets to release the female seed and restore the humors. She provides the example of John of Gaddesden, who said of nuns: “if she has a fainting fit, the midwife should insert a finger covered with oil of lily, laurel or spikenard into her womb, and move it vigorously about.” Further, Dominican friar Albertus Magnus surprisingly echoed this sentiment, calling on many women (not just nuns) to “use their fingers or other instruments until their channels are opened and by the heat of the friction and coition the humor comes out, and with it the heat.”

Again, there is hardly any discussion within these texts on the moral implications of sexual reprieve as a means to restore one’s health, emphasizing the extent to which sexual activity had become medicalized by physicians and religious clerics alike. However, while there seemed to be a general consensus around the belief that sex affected the humors, how it did was also varied. Sex was not always beneficial, nor was it always prescribed as a remedy. In the case of excessive sexual activity, and as will be evidenced in the following section, it was actually seen as problematic, although not for the sinful reasons as outlined in Christian doctrine.


The acceptance of sexual intercourse as a health remedy by physicians did not give men and women full license to engage in overzealous sex, regardless of whether an individual was married or not. Even Constantine, arguably one of the most sexually progressive religious clerics, set strict boundaries for sexual activity — dictating when (mornings are bad and nights are good) and how to have sex (missionary position) in a way that was least harmful. This suggests that sex could also be detrimental to individual health, causing an imbalance of the humors when in excess. The example of sexual promiscuity, as well as medical responses to it, indicates exactly that.

In a 6th-century treatise titled Wisdom of the Art of Medicine, which outlined several health maxims similar to the Salernitan Health Regimen, men are cautioned against engaging in sexual intercourse as they age and the “humors of the body decline and the heat diminishes,” especially if cathartics and other therapies have been used concomitantly. For example, if a man has undergone bloodletting, he should abstain from sex so that the restorative process is not intensified more than necessary, leading to more imbalance. Thus, sex in excessive amounts, promiscuity per se, was just as dangerous to one’s health as abstinence was for men and women.

On the other hand, evidence suggests that sexual intercourse was perhaps more dangerous than abstinence. Constantine, piggybacking off the ideas of Galen, warns against the dangers of too much sex, writing that “it is evident, then, that the animal that has intercourse to excess will rapidly expire and the one that has intercourse infrequently will live longer. For this reason, eunuchs are longer-lived, because they cannot have sex….” There is a point of tension here worth mentioning. He not only argues that excessive sex is medically detrimental and thus shortens one’s lifespan, but he is elevating the eunuch — one who does not engage in sexual intercourse at all — above the promiscuous in terms of longevity. While this seems to contradict his earlier arguments in favor of sexual activity as a means to restore bodily health, it does not imply any normative sentiment in regards to sexual intercourse in general, only in excessive amounts. He only states that those abstinent live longer, not necessarily that they are objectively healthy themselves. Thus, this aligns perfectly with the medicalized conception of sex, one that positions sexuality within the medical realm and deals with its complexities and nuances from a physiological, as opposed to moral, perspective.

Medical/Religious Synergies in Regards to Sex

Contrary to popular belief, the reconceptualization of sex as medically beneficial or harmful based on the theory of four humors did not immediately interfere (at least in a way that was significant) with Church teachings on sexuality. In fact, medical interventions that prescribed and regulated sexual activity often played into, accommodated and reaffirmed traditional sexual values. Women were encouraged, if possible, to marry so that they could engage in “regular, Church-sanctioned, procreative intercourse” with their husbands, thus sidestepping the moral question of sinful premarital sex. In cases where men or women could not marry (ie. monks and nuns), non-reproductive measures like masturbation and diet could be recommended so as to not offend Christian doctrine and their vows of purity.

On the other hand, just as medicine was not always hostile to religious sensitivities, church authorities were not always hostile to Western medical beliefs. To the contrary, the fact that many monks and religious clerics touched upon sex from a purely medical perspective, as evidenced throughout this paper, and that church penitentials often positioned masturbation and other sexual activities on a lower hierarchy of sinful acts which required penance, confirms what Cadden writes in The Meanings of Sex Difference in the Middle Ages, namely that:

Medicine reflected a clear and sometimes uneasy awareness of its environment. Its position sometimes opposed the interests of religion and society, as with the disapprobation of a monk’s continence or of a noble daughter’s virginity, but its flexibility as manifested in the provision of remedies for the ill effects of abstention prevented the outbreak of open hostilities. There was no warfare between medicine and other values. Nor was there cozy complicity.

Monks relied upon and used Western medicine in monastic environments to cure health ailments; secular physicians were cautious in intruding upon the moral and religious domains of ecclesiastical authorities. Thus, medicine and religion seemed to coexist peacefully in matters of sexuality; not perfectly, but effectively in a way that renders any notion of an outright “warfare” between both institutions historically inaccurate and short-sighted.

Like leprosy, the plague and other diseases that afflicted medieval people, sexual overindulgence and celibacy “posed a set of concrete issues with which medical authors dealt frankly and directly in relation to both sexes.” While authors like the abbess Hildegard of Bingen interpreted humors and medical ailments as divinely ordered, products of humanity’s fall from grace after Adam, so, too, did the opposite trend occur: physicians and clerics looking at previously moral and religious problems like sexual intercourse with a medical gaze. Emblematic of the active interplay between medicine’s natural causes and religion’s divine origins, what the medicalization of sex further illustrates is how both secular and ecclesiastical men set aside moral questions about sex and tapped into the same medical theories to see sex as curative in deficiency and harmful in excess.

This essay has been readapted from an original essay written by the author for a Princeton University course.


David C. Lindberg, The Beginnings of Western Science: the European Scientific Tradition in Philosophical, Religious, and Institutional Context, 600 B.C. to A.D. 1450 (Chicago, 1992), 324.

“The Salerno Regimen of Health,” in Faith Wallis, Medieval Medicine: A Reader (Toronto, 2010), 488.

Constantine the African, Constantini Liber de coat. El tratado de andrologia de Constantino el Africano, ed. Enrique Montero Cartelle (Santiago de Compostela: Universidad de Santiago de Compostela, 1983), 76–184 in Wallis, Medieval Medicine, 512.

Gargilius Martialis, Medicina de oleribus et poems, ed. Brigette Maire (Paris: Les Belles Lettres, 2002), pp. 14–15, 21–24, 28, 61–63, 72–74 in Faith Wallis, Medieval Medicine: A Reader, 37.

Ed. Gregor Maurach, “Johannicius. Isagoge ad Techne Galieni,” Sudhoffs Archiv 62.2 (1978): 148–74 quoted in Wallis, Medieval Medicine, 146.

Monica Green, The Trotula: A Medieval Compendium of Women’s Medicine (Philadelphia: University of Pennsylvania Press, 2001), 73.

Joan Cadden, The Meanings of Sex Difference in the Middle Ages: Medicine, Science and Culture (Cambridge University Press, 1995), 275.

John of Gaddesden quoted in Katherine Harvey, “Bad for the Soul, Good for the Body: Religion, Medicine and Masturbation in the Middle Ages,” Notches blog (November 2015),

“Sapienta artis medicina. Ein frühmittelalterliches Kompendium der Medizin,” Kylos 1 (1928): 103–13 quoted in Wallis, Medieval Medicine, 19.

Hildegard of Bingen, “Prophecy and Healing: The Meaning of Illness According to Hildegard of Bingen,” in Wallis, 357–358.

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