§4. Medical Empiricism
A self- styled medical empiricism emerges in Hellenistic times, after the death of Aristotle, though our earliest source for the argument between empiricists and rationalists is the first century ce Roman encyclopedist Cornelius Celsus.
He says medical empiricism began in the latter third century bce with Serapion, a pupil of the Alexandrian physician Herophilus, and the first doctor reputed to boast about being guided solely by experience. The disagreement between empiricists and rationalists is chiefly an argument about the medical value of signs. Rational signs owe their putative significance to hypothetical theories on the cause of disease. For instance, some condition of the countenance might be a sign of disease because it is a sign of a hypothetical cause of disease, like excess heat.27Empiricists discount such signs and rely instead on signs correlated with regularities of medical experience. Medicine, they say, is not concerned with the things that ratiocinative nous deals with. The only medically useful signs are remembered associations, in other words, “experience,” including induction and analogy, which are considered varieties of memory and not a flight into the hypothetical. Medical empiricists put greater stock in memory— what the practitioner has experienced—than in logic, or what they have never seen but infer. Thomas Hobbes, an Oxford graduate with a license to teach Aristotle’s logical works, epitomized the Stagirites concept of experience as “much memory, or memory of many things.” That is what medical empiricists say of their art—that it is an art of memory, the memory that comes only with experience, as experience. Here is Galen’s sympathetic explanation of the empiricist position:
When they have assimilated, not just twice or three times, but very many times, what has turned out to be beneficial on earlier occasions, and when they find out that, for the most part, it has the same effect in the case of the same disease, then they call such a memory a theorem and think that it already is trustworthy and forms part of the art.
But when many such theorems had been accumulated by them, the whole accumulation amounted to the art of medicine, and the person who had accumulated the theorems amounted to a doctor.28Galen emphasizes that the “experience” medical empiricism appeals to is long experience. Experience is written in the register of memory and the past, not given with present perception. Medical experience means “the knowledge of those things which have become apparent so many times that they are already theorems, i.e., when it is known whether they always have had that outcome, or for the most part, or ambiguously, or rarely” Experience takes its place in the empiricist tripod of accurate observations, a well-stocked library, and the collective memory of what has worked and what not.29
Medical empiricists were also known as mnemoneutikoi, memorists. According to the first empiricist theory of knowledge, to know a medical fact is to have observed it and to remember it in the appropriate way, which was not assumed to require reasoning or inference, expressing instead the power of memory. Generalization, for instance, is memory, not “hypothesis.” Memory rather than reason is capable of the entire complex experience that constitutes the medical techne, and fulfills some or even all of the functions Plato and Aristotle press their tradition to attribute to immaterial rational intellect.30
The Hippocratic formulation of this idea arises midway between the oldest version, in Alcmaeon, and its mature statement in Aristotle. In a fragment preserved in Plato, Alcmaeon writes, “ The brain provides us with perceptions of seeing and hearing and smelling: from these might come about memory and belief, but from memory and belief, if it has reached a state of rest, on the basis of these, knowledge comes about.” Galen says the medical empiricists take exactly this line. The difference between what is evident or apparent and what is known is the difference between what is perceived and what is remembered.
Memory produces not only belief but knowledge and it does so without inferences or a causal hypothesis.31Medical empiricists signaled the value of memory in the name they selected for the only sign they allow: hypomnestikon, commemorative, the kind of sign that makes us remember. Frede thinks the point of the term is that the use of these signs involves no inference. These signs “do not provide us with a premise for a bit of reasoning to the conclusion, but rather, given our experience of a constant conjunction, suggest the conclusion, more or less strongly.” These physicians were not simply opposed to anything that might be construed as reasoning. What they oppose is a claimed power of reason to go beyond observation to ideas of the imperceptible, which they think rationalistic doctors overvalue for good medical practice.32
Hippocratic authors did not call themselves “empiricists,” a usage that begins in Alexandria a century or more later, yet they require doctors to eschew dogmatism, admit failure, and diligently seek to enhance the corporate art and knowledge, their techne, and these are themes of later, selfconsciously empirical medicine. This inaugural empiricism is also the first notice in European science of the value of tentativeness and caution, admitting doubt and acknowledging mistakes, qualifying generality, with express wariness about unsupported claims. Doctors are reminded of the difficulty of their art. “It is not possible to have exact knowledge, nor to indicate at what time a patient will die, nor even whether this will be after a long or a short period.” Another doctor “would heartily praise the physician who makes only small mistakes: exactness is rarely to be seen.” That is an important principle for any kind of inquiry, and it is a lesson not to be learned from the classical Greek philosophers.33
Some of the treatises contain records of errors, “a quite unprecedented phenomenon,” according to G. E.
R. Lloyd. Describing a failed therapy for hunchback, one author writes, “I relate this on purpose: for those things also give good instruction which after trial show themselves failures, and show why they failed.” Another writes of a patient with a head wound, “It escaped my notice that he needed trepanning. The sutures which bore on themselves the lesion made by the weapon deceived my judgment, for afterwards it became apparent.” “No treatment that he received did him any good,” says another, and another, “It was impossible to do anything to help her; she died.”34Perhaps it seems paradoxical that confessions of failure should inspire confidence. Yet Robert Boyle in the seventeenth century knew this trope and encouraged it in writing up experiments for publication (§45). Cults do not admit failure. A stele at Epidauros, antiquity’s most celebrated Asclepeion, or religious site of healing, preserved seventy case histories, all successful, except for one supplicant who refused to deliver a gift intended for the god and developed complications. Hippocratic authors want everyone to understand that they are not like that, that their practice is not magic, not priestcraft, but a techne, a professionally disciplined body of technical knowledge, carefully tested and controlled by experience.35