Galen’s Rationalism, properly understood and practiced, involves an appropriation of experience, in that by taking hold of and building upon phenomena the doctor-philosopher achieves a superior type of knowledge, an art of medicine.  Insofar as this is the case then, Rationalism is inarguably a more robust theory of knowledge compared to Empiricism, which in fact is subsumed into this Galenic Rationalism.  On the other hand, however, if Empirical phenomena are not incorporated into the superior methods of Rationalist understanding, then to this same degree they are deficient and wanting.  This naked kind of Empiricism is exactly the target of Galen’s criticism, of which I present two arguments below.

The first of these criticisms can be subtle on a first reading, and deals with argument itself.  Galen says,

For it is not their view [the Empiricists] that one can judge the truth of the matters in question in these accounts, since they believe that evident perception and memory suffice for the constitution of all arts.  But, to judge such matters it is necessary to suppose that there is some power in us which is able to consider and to judge what is incompatible and what follows.  If, then, there is no such power in us, we should not endeavor either to produce arguments ourselves or to refute those arguments which have been argued badly (Outline of Empiricism 44 trans. Walzer, Frede).(1)

Galen is not here saying that Empiricists recuse themselves from the dispute about the role of reason in medicine; rather he is forcing the point that the Empiricists have no standing when it comes to arbitrating any dispute because they have nothing to arbitrate by, except inert experience.  In order to appeal to the superiority of Empiricism over Rationalism, one has to make use of reason itself, but this would appeal to something beyond experience and memory, a resource which Empiricism does not have.  In fact, Galen implies that Empiricists are unable to be consistent in their adherence to Empiricism, since even it requires “some power in us which is able to consider and to judge what is incompatible and what follows.”  Thus, even on a strictly Empiricist program, there must be judgments about what is similar or dissimilar, compatible or incompatible, consistent or inconsistent concerning the phenomena under investigation, if one is expected to categorize or understand the information.  In summary, to argue at all is to enter into the Rationalist camp.(2)

There is an equally clever, perhaps sophistic, argument against Empiricism which was mentioned earlier in the treatise as well, but gets it full narrative force in On Medical Experience.  Galen is attempting to use a traditional sorites-type argument and apply it to medical practice.  The puzzle is summarized as follows: if it is agreed that the art of medicine is constituted only by a number of experiences, at precisely what number of experiences do we say that a doctor has acquired the art of medicine?  He pesters the Empiricist to respond as to why a certain number of experiences is not sufficient to guarantee this art: is it 12, 40, 100 times?  No matter the number, though, says Galen, it will be a finite number.  He can then ask why it is that one less than this critical number is not sufficient to constitute the art.  More importantly though, he has shown a point of inconsistency in the Empiricist’s method which cannot be solved by experience.  The inconsistency is that the Empiricist’s initial position was that one experience was insufficient for the acquisition of the art.  But now when say the critical number is 50, in the process of passing from 49 to 50 experiences, that is, the addition of one experience, then the Empiricist claims that this single experience makes all the difference.  I take it this sorites argument appeals to Galen’s earlier contention that Empiricism, in its very nature, is not equipped to deal with arguments, since these lay outside the realm of phenomena.  Yet it also seems that Galen is pointing out something about the very nature of experience.  Experience, as the Empiricist wishes to have it in the medical art, is deeply limited in Galen’s view, because, were it not for the addition of something else at a given point during the procedure of induction, induction would blithely continue on ad infinitum with, quite literally, no reason for it to pause in its course.  The impetus for experiences to coalesce into an art cannot come from experiences themselves, no matter how numerous, but from some guiding rational principle that orders and arranges the information into a comprehensible whole.  This rational principle, of course, if it is discerned by a faculty specially designated to identify this rationality, need only be exposed to the faculty a single time for it to be properly identified.  This efficacy, a singular identification from a single exposure, is Galen’s point, and he is here forcing the Empiricist to concede it, whether it be Galen’s explanation of a Rationalist faculty or under the conditions of Empiricist induction, as this sorites argument would have it.

Footnotes:

(1) This text is extant only in a Latin translation by Nicolaus of Reggio in 1341.  I unfortunately do not have access to this text.

(2) There is not only an appeal to rational argument, but further, to a faculty, perhaps analogous to that between experience and the senses.  Thus there is both reason and the faculty of reason, neither of which the Empiricist can appeal to.  This argument plays right into Galen’s second objection as well, as I show.

References:

Galen. “An Outline of Empiricism.” Three Treatises on the Nature of Science. Trans. Richard Walzer and Michael Frede. Indianapolis, IN: Hackett Pub., 1985.

Galen. “On Medical Experience.” Three Treatises on the Nature of Science. Trans. Richard Walzer and Michael Frede. Indianapolis, IN: Hackett Pub., 1985.