Competing Theories of Spermatogenesis in Classical Greek Science

Hello everyone! This blogging thing has turned out to be a lot of fun! I really appreciate all the support I’ve gotten thus far– I’ve managed to scrape together almost 2000 hits and 27 followers in a matter of months!

You may have noticed that the posts have slowed down a bit lately. I think that with the amount of pressure I’m under at the moment, one post per month is about all I can handle for now. Anyway, I thought I would share a paper I wrote some time ago for a postgraduate seminar… The paper seemed to go down well, so I thought I’d call my mum to tell her the good news.

‘Oh, that’s nice,’ she said. ‘What was your talk about?’



‘Greek sperm.’

A long, awkward silence ensued.

I do hope you enjoy the paper rather more than she did! It’s not really original research. but it is rather an obscure area. Therefore, it’s perfect for a blog post. Enjoy!

Classical Greek conceptualisations of embryology and generation exerted powerful influences over both the development of European medicine and our understanding of the functioning of the human body. Spermatogenesis, the production of sperm, was an issue that was fiercely debated amongst writers of the Hippocratic Corpus and Aristotle.  Between them, they presented three competing ideas of the generation of sperm. The first was the Encephalogenetic theory, which postulated that sperm is produced in the brain. The second was the Pangenetic theory, which claimed that sperm is the product of all bodily humours combined. Finally, Aristotle’s Haematogenous school of thought supported the theory that seed originates from blood. (edit: It has been brought to my attention that the word ‘school’ might give the impression that Greek medicine was better organised than it was in reality. I’m just using the word to indicate a particular way of thinking). Yet certain Hippocratic authors gave equal credence to multiple theories of spermatogenesis simultaneously, with no attempt to reconcile them. Conversely, Aristotle fiercely disparaged Hippocratic pangenetic theories. Due to medieval and Renaissance biologists’ reliance on Aristotle and Hippocrates, the conflict between the disparate spermatogenetic theories continued until advancements were made in the field of microbiology during the Nineteenth Century. Pangenesis, for example, influenced Charles Darwin’s understanding of genetic inheritance. My paper will examine the theories of spermatogenesis which were put forward by Fifth and Fourth Century authors who entered the debate, particularly those of Aristotle and the Hippocratic School.

Adherents of the Encephalogenetic theory hypothesised that sperm is produced in the brain and is transmitted to the loins via the cardiovascular system. This idea probably predated Hippocrates, as Diogenes Laertius recorded it as an argument of Pythagoras.[1] Yet the idea was adopted occasionally in the works of the Hippocratic Corpus. For instance, as part of his excursus on the health problems particular to the Skythians, the anonymous Hippocratic author of On Airs, Waters and Places suggested that male infertility and sexual impotence were common among Skythian horsemen, due to the Skythians’ reputed routine of bloodletting from the cranium to treat swelling caused by hard riding. He stated his opinion that this process destroys the production of seed: ‘For there are veins alongside the ears, the cutting of which results in infertility.’[2] Admittedly, the author did not here explicitly state that he credited Encephalogenetic precepts. However, his identification of a causal relationship between interrupting blood flow from the head and sexual dysfunction implies that he observed Encephalogenetic principles to some extent.

On the other hand, followers of the humourist school of medicine often favoured the Pangenetic theory that sperm results from the combination of all bodily humours (black bile, yellow bile, phlegm and blood).[3] According to the work of the Hippocratic Corpus known today as The Seed, sperm is a type of foam produced by the subjection of bodily humours to heat and agitation.[4] Humourist writers reasoned that the combination of all four humours must be necessary for procreation since they considered each humour an essential component of a human being.[5]

Pangenetic theories regarding the formation and diffusion of sperm are most clearly articulated in The Seed. The author claimed that ‘The sperm of a man comes from all the liquid in the body.’[6] He went on to suggest that the most powerfully concentrated bodily humours are separated from those less potent and funnelled into the spinal column, ‘for there are passages that extend into it from the whole body.’[7] Once the four humours are combined in the spinal column, the fresh semen is then filtered to the kidneys. From there, it is transmitted via the testes and released through a special duct in the penis that, according to the author, is separate from the urinary tract.[8]

Though he did not accept the premise of Pangenesis, Aristotle catalogued in his treatise On the Generation of Animals four main arguments that prompted previous theorists to accept the Pangenetic understanding of spermatogenesis. Admittedly, using Aristotle as a source for Pangenetic theory is somewhat perilous, since he articulated Pangenetic theories specifically to debunk them. Yet the employment of Aristotle is necessary, as his work contains one of the few clear explanations of Pangenetic principles of genetic inheritance that has survived to the present day.

First, he noted Pangeneticists’ argument that the intensity of sexual pleasure that accompanies male ejaculation indicates all parts of the male body are involved in the production and release of semen. This was argued on the basis of a syllogism, that if the pleasure of orgasm came from less than the sum total of the body, it would not be so powerful.[9] Aristotle countered this syllogism with one of his own. He suggested that the orgasm that accompanies ejaculation in males would prove pangenesis only if male orgasm built gradually throughout intercourse; if sperm were drawn from the extremities of the body, he claimed it follows that orgasm ‘should occur not at the same time, but prior in some areas and afterward in other areas.’[10] Yet, as he wryly pointed out, male orgasm occurs only at the climax of intercourse. As far as Aristotle was concerned, the suddenness of the male orgasm and ejaculation implied that it was instead caused by ‘violent stimulation’ of the circulatory system.[11]

Secondly, Aristotle noted the Pangenetic contention that injuries are inherited, since damaged or abnormal parts of the body do not produce seed and ‘the part from which no semen comes does not get formed in the offspring.’[12] Aristotle demolished this argument by pointing out that deformities are not universally passed on from parent to child.[13] He did however, make the concession that ‘monstrosities’ arise in cases where deformities are congenital.[14]

Thirdly, he recorded the Pangenetic argument that children physically resemble their parents in many areas throughout the body, implying that sperm came from those areas.[15] Aristotle refused to credit physical resemblance as evidence for Pangenesis, commenting that certain parental characteristics appear in offspring which, as far as he could tell, cannot possibly arise from sperm.[16] He cited the examples of hair and nails being passed on to children. Being dead tissues, he considered hair and nails incapable of producing sperm, yet they are passed on from parent to child nonetheless.[17] Aristotle also attempted to present the acquisition by children of parents’ manners of walking and talking as evidence that Pangenesis was false, since behavioural patterns do not in themselves generate sperm yet are passed on regardless.[18] Aristotle also made the point that features of old age will manifest in offspring at the later stages of life even when they were not present in parents at the time of conception.[19] Furthermore, Aristotle pointed to the fact that children can resemble ancestors who played no direct part in their conception; thus, their physical characteristics are not predicated on sperm from their parents alone.[20]

Finally, Aristotle listed the Pangenetic precept that since all living beings are crafted from a whole, the same principle must therefore apply to individual parts of the body.[21] Thus as presented by Aristotle, the Pangenetic theory relied on a concept of preformation.[22] As far as he was concerned, Pangenetic theorists held that minuscule body parts exist in a dismembered state within sperm, which are then assembled into human form immediately upon implantation in the womb.[23]

Aristotle discredited this idea with the observation that limbs cannot live once they are detached from the whole.[24] Moreover if the parts are not dismembered, then semen (as the sum of all the parent’s body parts) would form a living creature in itself.[25] Therefore, if parents each contribute sperm that hold all the parts of the body in potentia, then people would be able to reproduce asexually.[26]   

On the other hand, it is worth considering that Aristotle’s account of Pangenetic belief regarding preformation does not entirely tally with the account of generation given in The Nature of the Child. This Hippocratic version is arguably more refined and more subtle than Aristotle would have his readers believe.[27] The Nature of the Child postulated that the parts of the body indeed exist within sperm, but in an undifferentiated state.[28] Rather than carrying a homunculus, The Nature of the Child suggested that seminal fluid contains raw material gathered from each part of the body. Only after conception might the parts begin to take shape from this amorphous mass, a process apparently initiated by respiration.[29]

Unlike the Encephalogenetic and Pangenetic theories, the Haematogenous school of thought, made popular by Aristotle’s Generation of Animals, held that the origin of sperm lies in blood.[30] It should be noted, however, that Aristotle was not the originator of this theory, for a simpler version of it is found in fragments of pre-Socratic philosophical works by Diogenes of Apollonia.[31] Since a version of the Haematogenous theory of spermatogenesis may be found in an earlier source, Aristotle was probably simply elaborating on a pre-existing notion through his teleological method.[32] Aristotle argued on the basis of his observation of various animal species that blood is formed from the ‘concoction’ or ‘ripening’ of foodstuffs in the belly.[33] Once liquefied by what Aristotle identified as ‘vital heat,’ the fluid undergoes further processing in the heart.[34] The Aristotelian theory held that a surplus of blood is produced by this process. In the cardiovascular system en route to its final site of excretion, this excess blood in turn is fermented into various practical fluids. Among these were sperm in men, as well as menstrual fluid and breast milk in women.[35]

While Aristotle was adamant in his insistence on Haematogenesis, the question of where sperm arises from prompted a great degree of uncertainty from some Hippocratic authors. This is suggested by their simultaneous inclusion of incompatible theories of spermatogenesis within their works. Von Staden suggests that this eventuated because the Hippocratic Corpus represents a transitional period in the history of Greek medicine, dealing with both long-held traditions and emerging understandings of the human body.[36] The tension between old and new theories of spermatogenesis is most evident in the Hippocratic work On Airs, Waters and Places, whose author included both the Encephalogenetic and Pangenetic theories side-by-side. As previously mentioned, Airs, Waters and Places suggested a causal relationship between the act of bloodletting from the head and sexual impotence, suggesting a strong degree of belief in the older Pythagorean tradition of the brain as the source of sperm.

Yet the author of Airs, Waters and Places had earlier made it clear that he supported the Pangenetic theory of spermatogenesis.[37] The Pangenetic aspects of Airs, Waters and Places are incorporated in the author’s discussion of the factors which he believed to cause ethnic diversity, particularly his lengthy tract on the peculiar characteristics of the tribe he identified as Makrokephaloi, or ‘Longheads.’ Here he quite explicitly stated that ‘seed issues from every region of the body, healthy seed from healthy parts, unhealthy seed from the unhealthy.’[38] He argued this on the basis that the Makrokephaloi apparently engaged in the ritual of fixing tight bandages around the soft skullcaps of their newborns, applying pressure around the pliable bone in order to elongate their heads permanently.[39] Through the process of pangenetic spermatogenesis he suggested that elongated skulls had become an inherited trait among Makrokephaloi as damaged seed from their skulls resulted in the same damage being projected onto their children.[40]

It should be noted that the author of Airs, Waters and Places made no attempt to reconcile the disparate Encephalogenetic and Pangenetic theories, but presented them both unabashedly.[41] This might be interpreted as evidence that the author was at a loss as to which spermatogenetic theory he should accept. Without anatomical knowledge of the reproductive system, either theory could have been true. In this situation, he perhaps was willing to hedge his bets by including both in his work.

Similarly, the Hippocratic writer of the The Seed attempted to deal with the disparity between the Encephalogenetic and Pangenetic theories by combining them. As previously mentioned, the author of The Seed adopted the Pangenetic stance that male sperm results from all bodily humours undergoing heat and movement.[42] However, the author also attempted to incorporate the Encephalogenetic ideation of the brain as a reproductive organ without going so far as to suggest that sperm is a direct product of the brain. Instead he believed that seminal fluid, having been produced throughout the body, is channelled upward via the vascular system to the cranium for filtration in the brain, which acts as a kind of spermic reservoir. According to The Seed semen, once filtered in the head, passes downward through the spinal column to the loins, there to be somehow released through sexual intercourse.[43] The precise mechanics of ejaculation were not described at all.

The attempt in The Seed to bring together the Encephalogenetic and Pangenetic tenets failed to produce a fully choate explanation of spermatogenesis and did not engender any form of consensus regarding the production of seed.[44] Although his attempt to synthesise the ideas was admirable in its ingenuity, the author’s approach was somewhat arbitrary. He made no attempt to explain the basis on which he selected aspects from each theory, seemingly looking only to form a coherent narrative of spermatogenesis. To some extent, the unique spermatogenetic theory proposed in The Seed may be seen as the synthesis of the opposing Encephalogenetic and Pangenetic viewpoints through the dialectic process. In the Greek philosophical tradition as in contemporary academia, the synthesis of ideas formed through the dialectical process ideally resulted in consensus. This did not occur in the case of The Seed. Though the author accomplished an explanation of spermatogenesis that held some degree of internal consistency, no other surviving work of antiquity repeated his view.

Interestingly, neither the Hippocratic Corpus nor Aristotle attributed the gonads any active role in the creation of seed; rather as far as they were concerned the testicles serve a purely ancillary function in spermatogenesis.[45] The Hippocratic author of The Seed came closest to assigning the testes an active role in sperm production, identifying the destruction of the ‘spermic passage’ through the testicles as a reason for eunuchs’ impotence.[46] Yet he did not directly state that the testes themselves are the source of sperm. Rather, he argued that they serve a mechanical role in intercourse. As he said,

Eunuchs are unable to have intercourse for this reason: that the passage of the seed itself is destroyed, for there is a passage through the testicles. Also, there are compact, slender sinews running from the penis to the testicles, which constrict to hoist up and let down the penis. And these in surgery are cut, and it is by this that eunuchs begin to be impotent. On the other hand, the spermic passage of those (whose testicles) are wiped out becomes obstructed, for the testes are petrified; and the ligaments, having become hardened and dull by the petrification, are no longer able to constrict and loosen. (Hippoc. Sem. 2.)

On the other hand, Aristotle went so far as to liken the testes to loom weights.[47] To explain Aristotle’s metaphor, he believed that testes serve to extend the passage of sperm within the veins. Rendering the journey of the seed more tortuous before its eventual ejaculation would, he reasoned, give the seminal residue more time to concoct and thereby render it stronger and more effective in bringing life to an embryo.[48] As far as Aristotle was concerned, this process would also bring the benefits of curbing premature ejaculation and moderating excessive sexual passion.[49]

Spermatogenesis was a matter that provoked great speculation and debate between Aristotle and the Hippocratic writers, as shown by their competing theories of Encephalogenesis, Pangenesis and Haematogenesis. This lack of harmony regarding spermatogenesis would affect later Greco-Roman authors such as Herophilus, Soranus, Tertullian, Galen and Vindicianus. Indeed, the concept of preformationism would continue to impact on understandings of generation even with the published identification of spermatozoa under a microscope by the Dutch microscopist and haberdasher Antonie van Leeuwenhoek in 1677 AD.[50] Crucially, the Pangenetic concept of spermatogenesis would underpin Charles Darwin’s understanding of genetic inheritance.[51] Pangenesis would not be conclusively disproven until 1871, through experimentation on rabbits by Darwin’s relative Francis Galton.[52]


Ancient Sources

Aristotle (ed. H.J. Drossaart Lulofs). 1965. Aristotelis De Generatione Animalium, Clarendon Press: Oxford.

Aristophanes of Byzantium (ed. A. Nauck and W.J. Slater). 1986. Aristophanis Byzantii Fragmenta, Walter de Gryter: NY and Berlin.

Diogenes Laertius, (ed. H.S. Long).1964. Diogenis Laertii Vitae Philosophorum, Clarendon Press: Oxford.

Hippocratic Corpus (ed. E. Littre). 1839-1861. De Aera, Aquis, Locis, in Oeuvres Complètes d’Hippocrate, J.B. Bailliere: Paris.

Hippocratic Corpus (ed. E. Littre). 1839-1861. De Morbo Sacro, in Oeuvres Complètes d’Hippocrate, J.B. Bailliere: Paris.

Hippocratic Corpus (ed. E. Littre). 1839-1861. De Natura Pueri, in Oeuvres Complètes d’Hippocrate, J.B. Bailliere: Paris.

Hippocratic Corpus (ed. E. Littre). 1839-1861. De Semine, De Natura Pueri, De Morbis IV, in Oeuvres Complètes d’Hippocrate, J.B. Bailliere: Paris.

Modern Sources

Balm, D. and Gotthelf, A. 1992. Aristotle’s De Partibus Animalium I and De Generatione Animalium I: With Passages from II-1.3, New York: Oxford University Press.

Boylan, M. 1984. ‘Galenic and Hippocratic Challenges to Aristotle’s Conception Theory,’ Journal of the History of Biology 17: 83-112.

Bulmer, M.G. 2003. Francis Galton: Pioneer of Heredity and Biometry, Baltimore: Johns Hopkins University Press.

Cilliers, L. 2004. ‘Vindicianus’ Gynaecia and Theories on Generation and Embryology from the Babylonians up to Graeco-Roman Times’, in H.F.J. Horstmanshoff and M. Stol eds., Magic and Rationality in Ancient Near Eastern and Graeco-Roman Medicine, Boston: Brill Academic Publishers, 343-367.

Darwin, C. 1868. The Variation of Animals and Plants under Domestication, 2 Vols. London: John Murray.

Dean-Jones, L. 1994.  Women’s Bodies in Classical Greek Science, Oxford: Clarendon.

Dobell, C. 1932.  Antony van Leeuwenhoek and His “Little Animals,” New York: Russell and Russell.

Mayr, E. 1982. The Growth of Biological Thought: Diversity, Evolution, and Inheritance, Cambridge, Mass, Belknap Press.

Von Staden, H. 1989. Herophilus: The Art of Medicine in Early Alexandria, Cambridge, NY, New Rochelle, Melbourne and Sydney: Cambridge University Press.

[1] Diog. Laert. 8.28.

[2] Hippoc. Aer. 22.

[3] Mayr 1982: 636.

[4] Hippoc. Sem. 1.

[5] Hippoc. Sem. 3.

[6] Hippoc. Sem. 1.

[7] Hippoc. Sem. 1.

[8] Hippoc. Sem. 1.

[9] Arist. Gen. an. 721b15-20.

[10] Arist. Gen. an. 723b33-724a5.

[11] Arist. Gen. an. 723b34.

[12] Arist. Gen. an. 721b20-22. This is a reflection of Hippoc. Morb. Sacr. 5, which argues that predisposition toward sickliness may be carried over generationally because sickly seed propagates sickness in a child.

[13] Arist. Gen. an. 724a.5-10.

[14] Arist. Gen. an. 769 b.25-30.

[15] Arist. Gen. an. 721b22-23.

[16] Arist. Gen. an. 722a4-5.

[17] Arist. Gen. an. 722a5-10.

[18] Arist. Gen. an. 722a5-10.

[19] Arist. Gen. an. 722a5-10.

[20] Arist. Gen. an. 722a5-10.

[21] Arist. Gen. an. 721b25-30.

[22] Boylan 1984: 90.

[23] Arist. Gen. an. 722b7-30.

[24] Arist. Gen. an. 722b 4-5.

[25] Arist. Gen. an. 722b22-24.

[26] Arist. Gen. an. 722b13-14.

[27] Dean-Jones 1994: 163.

[28] Hippoc. Nat. puer. 7.

[29] Hippoc. Nat. puer. 7.

[30] Arist. Gen an. 726b10.

[31] Ar. Byz. 64B6DK. This surviving fragment of Third Century commentator Aristophanes of Byzantium’s epitome of Aristotle’s History of Animals gives a tantalising indication that the idea of Haematogenesis originated with Diogenes of Apollonia.

[32] Von Staden 1989: 290.

[33] Arist. Gen. an. 726b1-5.

[34] Arist. Gen. an. 726b 10-13.

[35] Arist. Gen. an. 776b 25-30; Cilliers 2004: 352.

[36] Von Staden 1989: 290.

[37] Hippoc. Aer. 14.

[38] Hippoc. Aer. 14.

[39] Hippoc. Aer. 14.

[40] Hippoc. Aer. 14.

[41] Von Staden 1989: 290.

[42] Hippoc. Sem. 1.

[43] Hippoc. Sem. 1.

[44] Von Staden 1989: 290.

[45] Von Staden 1989: 290.

[46] Hippoc. Sem. 2.

[47] Arist. Gen. an. 717a35-38.

[48] Arist. Gen. an. 717a29-31.

[49] Arist. Gen. an. 717a29-31.

[50] Dobell 1958: 104.

[51] Darwin 1868: 357.

[52] Bulmer 2003: 116-118.

About Futurus Essay

Julian Barr is a PhD student of Classics at the University of Queensland. His research interests are wide, but generally revolve around the Roman Empire and its literature. His research interests include but are not limited to: Second Sophistic literature, ancient conceptualisations of human reproduction, and early Christianity. He is in the early stages of a research project concerning the portrayal of unborn babies by the Roman African author, Tertullian. He also teaches part-time, and serves as an occasional museum minion. He also happens to be a father of two rambunctious toddlers, and is husband to an extraordinary woman.
This entry was posted in Ancient History, Gender relations, Philosophy and tagged , , , , , , , , , , , , , . Bookmark the permalink.

5 Responses to Competing Theories of Spermatogenesis in Classical Greek Science

  1. fluff35 says:

    You think you’ve got trouble with your mum; imagine the look on my mum’s face when I told her I’d got a prize for an article on masturbation!

    • Goodness, Helen King! Hello! Haha, that is hilarious about your mum’s response to your article. I look forward to reading it. Thanks for linking. Incidentally, I just finished reading your 1990 article for G.R. Dunstan’s book, ‘Making a Man: Becoming Human in Greek Medicine.’ I really enjoyed it! There is relatively little secondary material on ancient embryology, so I always jump for joy when I find it. :)

  2. Helen King says:

    You are so right about the lack of secondary lit on the subject; it would be interesting for a future blog post to speculate about why that is. incidentally, I’m not sure why you’ve gone for that phrasing ‘the school of…’ While you may have just meant ‘some writers seem to have had a similar idea’ there’s a risk that readers will think ancient medical thinking was a lot more organized than it was!

    • Hmm, that is a good thought. I think when I gave the speech I said off the cuff explaining about my use of the word ‘schools.’ But of course, that didn’t come up in the written form, and I had forgotten about it. Thanks for pointing that out– I’ll edit the post.

      I wonder if there is such little secondary lit because it’s a topic that makes people uncomfortable? Which is odd, given how liberal the English-speaking world is about sex and sexuality in general. But when I’ve given this paper and others, audience members usually either squirm or guffaw. I can understand why people might be a bit squeamish about some of the stuff I’ve presented on abortion as it’s such a divisive issue, but honestly, I’d have thought we’d all grown up by now on talking about where babies come from…

      • Helen King says:

        interesting to speculate, isn’t it? I agree, there’s still a lot of sniggering around a topic like this, and I am not immune – when I was in the Netherlands a few years back I found a great leaflet taking the tourist round sites associated with Leeuwenhoek and I could not resist referring to this as the Sperm Trail… I do wonder whether another problem is that the Greeks just seem so quaint to us now we know about eggs and sperm? The tendency of medical history to ignore the bits that were wrong and focus on the bits where the Greeks and Romans almost but not quite got it ‘right’ is very instructive – but on this particular aspect, the Hippocratic material on both parents contributing and why resemblance happens could be seen as an almost but not quite right moment…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s