When I first came to Rome I found certain physicians who avoided phlebotomy so sedulously that sometimes even when a person was suffocating from plethos they refused to use the remedy. In the case of a woman almost twenty-one years old, who had a red face and a slight cough and already some difficulty in breathing, as a result of suppression of the menstrual catharsis, I found them lightly binding her limbs with woollen bandages and ordering her to fast, but neither using phlebotomy themselves nor permitting me to do so. Since they were more trusted than I was because of their intimacy with the woman's family and their seniority, I gave up for the time being the attempt to convince them concerning phlebotomy; I did, however, enquire whether there would be any objection to provoking a flow of blood to the uterus by means of drugs with the power to effect this. When they agreed, I at once sought out the patient's usual midwife and urged her to make use of them. She told me, however, that she had used them as the occasion demanded, when the monthly purgation was expected to occur, and mentioned the drugs she had applied to the woman; they were all of approved quality, so that no one could think the treatment had failed because of their weakness.

It seems to me to be a question well worth investigating, why on earth Erasistratus, who was, after all, so competent in the other branches of the Art, and so meticulous about the minutest detail as to describe even the boiling of certain vegetables and of plasters – matters on which it would have sufficed any one else just to say what was essential and to omit the mode of preparation, as a minor point which anyone could pick up as he went along – why Erasistratus, in the case of such a powerful and important remedy as phlebotomy, and one that was esteemed by the ancients as in no way inferior to the most effective of all, has nothing to say. The fact is that the word K148 phlebotomy is scarcely to be found in any work of his; the one exception is in his book on bringing up blood, but even here he mentions it more, it would seem, in passing than as something he was considering with the care it deserves.

Galen (c. ad 129–200) was a Greek from Pergamon in Asia Minor. Because of his habit of putting autobiographical details into his works, we know that he was the son of a prosperous architect, Nikon, who named him Galenos (mild), perhaps in the hope that he would turn out different from his mother, who was a shrew. He speaks of his father with respect; he gave him an excellent education in literature, philosophy and the sciences, and finally sent him to Alexandria to study medicine after being advised in a dream to make him a physician. After a spell in Pergamon as medical officer to the gladiators, Galen went to Rome in 162 and quickly established a large and fashionable practice; the second bloodletting work gives a lively account of how he did it. It was not long before he was attending the emperor Marcus Aurelius, who had, if we can believe Galen, some very complimentary things to say about him. Galen wrote a short work, That the Best Physician is also a Philosopher, in which he condemned the ignorant and materialistically-minded doctors of his time, and urged physicians to emulate Hippocrates, who, at least according to Galen, had despised possessions and the pleasures of the table and the bed, and laboured unceasingly in the pursuit of knowledge.

No attempt at an exhaustive analysis of the writers between Hippocrates and Galen will be made here. Only a few will be considered; the aim is merely to illustrate the divergent opinions that were prevalent.

Whether or not Celsus was himself a physician, and whether his work is his own or a translation of a lost Greek original, it is of the greatest value in reconstructing medical opinion between the Hippocratic writers and Galen. In addition to many incidental references he devotes a chapter to venesection, which opens with the significant remark: ‘It is not new to let blood by cutting a vein; but that there is hardly any disease in which blood is not let, is new.’ This is, in effect, Galen's indication from the severity of the disease, regardless of its nature; his primary indication for bloodletting is the presence, or indeed only the expectation, of any severe disease whatsoever. According to Celsus this was in his time – some two centuries before Galen, unless he is reproducing an earlier work – a new concept. It cannot be Hippocratic, since Celsus describes Hippocrates as ‘the most ancient author’. As we have seen, the idea appears in the Corpus only in the Appendix to Regimen in Acute Diseases, which most scholars think spurious, although Galen says that this particular statement is good Hippocratic doctrine; this does not apply, however, to everything else in the treatise. It has already been shown that the Hippocratic writers used venesection far less extensively than Galen did, though Galen would like us to think otherwise; Celsus confirms this opinion.

It has been shown in the previous chapter that although the Hippocratic writers unquestionably made use of venesection, they mention it only briefly and in passing, neither offering a rational explanation for its use nor listing the indications. Galen is more systematic. From a study of all his references to venesection it is possible to extract a good deal of information on his practice, and to determine not only what he did but also sometimes why he did it. His indications will be considered first.

In brief, Galen regards venesection as an evacuant remedy to be used in certain patients with plethos, though not in all. Suppression of wonted evacuations of blood, such as the menses or bleeding piles, may lead to plethos, which in turn, if not dispersed, may result in inflammation. Apart from these considerations, any severe disease is an indication for venesection, not only when established, but even when foreseen or expected; thus venesection may be used prophylactically in healthy subjects. Galen employs the remedy widely in fever. It is further used as a revulsive or derivative remedy, to direct blood away from or towards a particular part; and a number of pathological conditions are specifically mentioned in which it is applied. These indications will now be considered in more detail.

As an evacuant, Galen says, venesection is selective; it empties only the veins, whereas starvation leads to the evacuation of the whole body, a process attended with many troubles for the patient. Besides, venesection acts at once, whereas starvation is slow and the weakest of all evacuant remedies; Galen remarks later that it does not evacuate directly at all.

In the foregoing chapters Galen's opinions on venesection have been collected from his surviving works and compared with the views of the Hippocratic writers and of some of his other predecessors and contemporaries. What has not been resolved, and probably cannot be certainly decided at all, is the origin of Galen's opinions. Although he has a profound respect for Hippocrates, his opinions on venesection are Hippocratic only in the sense that they are those of a fictitious Hippocrates whom Galen has constructed for himself. Although the seeds of his ideas are to be found in the Corpus, they have grown by the time of Galen into something far bigger and more organised than is found in the Hippocratic writings. It is not clear where and when this growth took place. Although Celsus, like Galen, makes more extensive use of venesection than the writers of the Corpus do, his practice is in many ways quite different from Galen's, and the same can be said of Aretaeus, Antyllus and Soranus. What, then, was the origin of Galen's peculiar methods and beliefs? They are not truly Hippocratic, and a study of a few surviving sources between the writers of the Corpus and Galen suggests that they were far from universal among practitioners of ability and reputation. Where, then, did they come from, and why did he hold them so tenaciously?

This question might best be answered with another: Why did Galen succeed in his practice?

An aim of this work has been to examine, not only Galen's opinions on bloodletting, but also the reasons why he held them; it is therefore necessary to consider whether he could have been justified in believing what he did. Galen, like most other practitioners of his time, used phlebotomy as an evacuant remedy in a great variety of diseases; he also employed it as a revulsive in a way that would seem quite incompatible with his knowledge of anatomy, yet which can be shown to have been justified in the light of the knowledge of his time. Is there any scientific justification for his use of venesection as a general evacuant, taking into account that the conditions under which Galen practised were different from those now prevailing? The arguments to be put forward would not be accepted by all authorities today; it is nevertheless however possible for a professional haematologist, making use of discoveries in medicine in the last thirty years, to put up a case of sorts for Galen's use of venesection as an evacuant remedy. Any such retrospective evaluation must, of course, be highly speculative. Two separate arguments can be used; one concerns resistance to infection, while the other is rheological. Infection will be considered first.

Most physicians today, if asked whether there were advantages to the patient in being anaemic, would probably not be able to think of many. And although most would certainly agree that degenerative disease of the heart and arteries is less prevalent in the undernourished, the orthodox view is that impaired nutrition makes for greater susceptibility to infectious disease.

This work originated from an interest in the history of ideas in medicine. I wanted to find out why our forefathers, almost to a man, believed that the proper way to treat most diseases was to remove blood from the patient, and as there was to my knowledge no published translation of Galen's three bloodletting works in any modern language, I made one from the Greek of Kühn's edition, and went on to consider where his ideas came from and how they developed in the course of a long and active life. The material was used in 1978 as a dissertation for the degree of M.A. in classics from the University of Natal. Subsequently the translations have been revised, and the discussion rewritten to make it more accessible to the general reader. An introductory chapter on Galen's system of pathology, based on subsequent reading, has been added, and the passages quoted in the text in Greek and in modern languages other than English have been translated. Although unfamiliar old terms are explained when first encountered, they have all been collected into a glossary for easy reference, together with such modern technical terms as may be unfamiliar to the non-specialist.

Kühn's text is corrupt in many places, and only one of the three works has had any critical attention. I have therefore examined a number of the manuscripts and early printed editions, which clear up some of the difficulties. I must make it clear, however, that the only aim has been to improve the translations, not to establish texts; I am not a philologist, even by inclination.

The dating of the three works will be considered later, but it is clear that the first work, the De Venae Sectione adversus Erasistratum, was composed soon after Galen's first arrival in Rome; it is representative, therefore, of his youthful opinions. There is nothing in this work to suggest that Galen, at that stage of his life, considered using any evacuant remedy other than phlebotomy at the onset of the patient's illness. He agrees with Erasistratus that it is necessary to empty the plethos; the only question is by what means it should be evacuated. ‘I have always thought that once evacuation has been agreed on, the easiest and most prompt remedy is to open a vein, since in this way the inflammatory matters, and these alone, are evacuated as quickly as possible.’ All patients with plethos, he says, are most quickly and effectively treated by opening the veins; although Galen mentions alternative remedies used by Erasistratus, there is no indication that he uses any of them himself in these circumstances. Not only the physicians of the rationalist sect, but also the empiricists, all use venesection; even Asclepiades, who condemned all the dogmas of his predecessors and described the Hippocratic methods as an exercise in death. It is in use in most diseases and the most acute, and Hippocrates himself, ‘whom we regard as the leader of all the distinguished men in the profession, and the other men of old clearly did use it’. The ancients, in Galen's opinion, thought it nothing less than the most effective of all remedies.

At the beginning of his first work on venesection Galen expresses his surprise that Erasistratus, a man so punctilious in matters of detail, should have mentioned venesection only once in all his works, and at that only in passing; for, says Galen, it is a remedy of such strength and efficacy that it was regarded by the ancients as nothing less than the most effective of all. It is made clear later that the ancients to whom he refers are, in fact, Erasistratus' predecessors in the profession, including Hippocrates; Galen frequently mentions Hippocrates' use of the remedy in this work, observing that he employed it in most diseases and in the most acute, and that even Asclepiades, who rejected almost all the other methods of Hippocrates, nevertheless still made use of venesection. In another work Galen maintains that venesection has been dealt with very completely by Hippocrates. He is not alone in this opinion. Littré observes: ‘When we enquire which remedies, among the many that were used, are most frequently mentioned as having been applied, we find that bloodletting and the evacuants – emetics and, in particular, purgatives – play the principal role in the therapy of the Hippocratic physicians, and hence of Hippocrates himself.’ Adams expresses a similar opinion in his commentary on Paulus Aegineta. ‘We have had occasion frequently to remark’, he says, ‘that Hippocrates practised venesection freely in various diseases. He has left no treatise, however, expressly on the subject.’

The impression conveyed by both these nineteenth-century writers, and by Galen himself, is that the Hippocratic writers frequently mentioned venesection, and used it freely.

Those who intend to use phlebotomy must consider first of all how many states of the body there are that call for evacuation. The next question is, which of these states require evacuation by phlebotomy; for there are many conditions, some of which need some other sort of evacuation, and certainly not bloodletting. The third problem is to decide which patients can stand the evacuation without harm, since sometimes the patient's condition demands phlebotomy, yet he cannot bear it either because of his stage of life, or the season of the year, or the nature of the country, or because of some disorder of the mouth of the belly. (This is often miscalled the stomach; in the interests of brevity, however, I shall nevertheless use the term from now on in the whole of this work). There are also some who cannot bear phlebotomy because of their general habit of body, even though by reason of their disease they need it very much. If we are to draw such distinctions, we must consider each occasion on its merits, just as we do with any other remedy. Our next question concerns the veins that are to be opened, since extensive research has been undertaken to decide whether it makes no difference which vein one chooses to cut, all being equally helpful in all conditions, or whether, as Hippocrates and the most celebrated physicians thought, it makes a great deal of difference whether one opens this one rather than that.

In Galen's own time, some proponents of venesection believed that it was immaterial which vein was opened, since the same effect could equally well be obtained by using any of them; others, Galen among them, thought that it made a great deal of difference which vessel was used. Hippocrates and the most celebrated physicians, he says, were of this opinion also. This is not an isolated opinion of Galen's; he expresses it in all three of his works on venesection, and he makes further mention of specific sites for bloodletting in the De Sanitate Tuenda, the De Methodo Medendi, Ad Glauconem de Methodo Medendi, and his commentary on the Aphorisms. Now Galen was an expert anatomist, and his view of the structure (as distinct from the function) of the vascular system was, except in insignificant detail, that of the anatomist of today; yet he approved of practices of revulsive phlebotomy which, it would seem, must be quite inconsistent with such a view of vascular anatomy. To try to understand why he did this it will be necessary to summarise not only his own anatomical opinions, but also those of some of his predecessors, particularly those who offered clear accounts of the peripheral vessels.

Since the vessels contain blood, and since blood has been a subject of interest to man from the earliest times, we find some reference to blood-vessels in the earliest Western literature. Homer describes how Antilochus, leaping on Thoon from behind, cut right through the vein that runs straight along the back till it arrives at the neck.