This small volume is a close and detailed look at the closing chapter of book 2 of Sextus Empiricus’ Outlines of Pyrrhonism (2.229-259), on sophismata, translated “fallacies”. Sextus’ chapter lays out the position of Sextus’ dogmatic opponents, that logic is essential for resolving fallacies, and then gives his reply. Johanna Schmitt aims to clarify the nature of the dogmatic view that is the target, and as far as possible its adherents (whom Sextus does not name), as well as analyzing Sextus’ counter-arguments and making precise their purpose. A particularly interesting suggestion is that one of Sextus’ primary goals is to challenge the view advocated by Galen, that the good doctor needs to be accomplished in logic in order to guard against fallacies in medicine.[1]
Following an introduction, the book has three chapters. The first chapter discusses the dogmatic position on fallacies as Sextus presents it. Sextus does not name his opponents, referring to them simply as “the dialecticians”. Schmitt considers what we know of the views on fallacies held by Aristotle, the Stoics, and Galen, and concludes that Sextus does not have any particular school as his target, though the Stoics are clearly in the mix to some extent. The dogmatic position Sextus lays out holds that fallacies are false arguments that appear plausible (PH 2.229). What it means for an argument to be “false” is not entirely clear, since one of the four main types of fallacies identified here is referred to as “akin to something false” (PH 2.230). Schmitt tentatively proposes (22) that a false argument is one that either has at least one false premise or is not valid (or both). But this does not seem quite right, since the argument that is “akin to something false” is both valid and sound; its problem is that it sounds preposterous—its conclusion is “ ‘The doctor qua doctor kills’ is not nonsense” (PH 2.230)—because of an ambiguity in the term atopon, “nonsense”, which in Stoicism can be used to mean “meaningless” (which “the doctor qua doctor kills”, being a well-formed sentence, is not, PH 2.233), but can also mean “absurd”. So perhaps “false” should be understood still more broadly in some sense such as “leading one astray”.
The dogmatists’ fourfold classification of fallacies is in terms of the conclusions to which they lead, which, as Schmitt points out, is a curious approach; one might think that it would be more useful to classify them in terms of the kinds of logical deficiencies they exhibit, which is what the Stoics, Galen, and (at least to some extent) Aristotle appear to have done. Schmitt suggests in section 3 of the chapter that the Stoics may nonetheless have had an additional interest in classifying them in terms of their conclusions, given their concern for taking care not to assent to anything rashly, which might point to a Stoic source. There is no other evidence to confirm or disconfirm this suggestion, but the fact that the Stoics are Sextus’ most frequent dogmatic target, often attacked without being named, gives it some plausibility.
The second chapter moves to Sextus’ response to the dogmatic position. His argument is that, contrary to what the dogmatists claim, dialectic is not an all-purpose means for solving fallacies. When the fallacies are in fields that demand special expertise (technê), it is those skilled in the expertise in question, not the skilled dialectician, who is in a position to solve them. As for the fallacies that dialectic is able to solve, their solution is useless anyway, since they are of no practical consequence. Having introduced the dogmatists’ four main types of fallacies, with an example of each, Sextus explains their solutions to the examples (PH 2.232-235), and Schmitt treats this as part of his counter-argument, these being fallacies whose solution is useless. This is a little surprising, since Sextus does not state his response to the dogmatists, including the point about uselessness, until after this exposition (PH 2.236), and one might rather consider it as part of his description of the dogmatic position (and chapter 1, rather than chapter 2, as its natural place). But the fallacies in question do certainly belong in the category of fallacies whose solution Sextus would regard as useless, and the chapter offers a close analysis of each.
As examples of fallacies whose solution is not useless, but which dialectic is powerless to solve, Sextus gives two examples of fallacies in medicine (PH 2.237-240). This is not surprising, seeing that he was himself a practitioner of the Empiric school of medicine.[2] Schmitt has more to say about this choice in the following chapter, but as instances of fallacies demanding specific expertise for their solution, they clearly serve the purpose. In both cases, the solution depends on drawing a distinction (which the fallacy elides): in the first case, between two different uses of the term “abatement” (parakmê), which might refer either to the fading of the entire disease or of a particular phase of it, and in the second case, between treatment of the core conditions of a disease and treatment of its symptoms. Sextus says that doctors are able to do this because “they grasp the interconnection [parakolouthêsin] between things” (PH 2.236). Since he is here distinguishing between the doctor’s (or other expert’s) grasp of the subject and the dialectician’s ability, parakolouthêsis cannot refer to logical interconnection, but to close empirical relationships among the matters under consideration. Sextus uses the corresponding verb when he says that tranquility (ataraxia) followed (parakolouthêsen) suspension of judgment as a shadow follows a body (PH 1.29); again, there is a close relationship, but not a logical one. Returning to his treatment of the medical examples, he does say that the doctor can see that the premises of the first fallacy “lack connection” (diêrthêsthai, PH 2.238), which is a Stoic term for a lack of logical connection; but this may be a cheeky way of indicating that the doctor is in no way inferior to the dialectician when it comes to handling fallacies. Schmitt’s treatment of these questions (section 2.2.3) is acute and insightful.
The one topic that I think might have deserved more emphasis in this chapter is the distinction Sextus draws between theoretical discussion and ordinary life. The fallacies dialectic is able to solve are useless to solve because they have no practical import. Sextus mentions some more of these (PH 2.241-244) after he has discussed the medical examples. He says that the skeptic can generate a situation of “equal strength” (isostheneia), and hence suspension of judgment, at the theoretical level between the conclusions of the fallacies and ordinary experience (PH 2.244). But when it comes to living one’s life, he adds that people simply ignore them (PH 2.244-245). Schmitt mentions Galen’s reliance on perceptual experience in the face of fallacies, but Sextus’ own typical reliance on the way things appear would have been an aspect of his response worth highlighting.
Speaking of Galen, the third chapter extends this account in an intriguing way, giving a further motivation for Sextus’ focus on medical examples. Schmitt documents Galen’s insistence that the good doctor must master all the main areas of philosophy, including logic, and one important reason for mastering logic is to enable one to find the solutions to medical fallacies. Galen, then, adopts a position diametrically opposed to Sextus’: it is not only medical expertise that is needed to solve medical fallacies, but also logical expertise. Sextus is generally thought to have lived at roughly the same time as Galen, though neither ever refers to the other. The indications Schmitt offers on Sextus’ dates (72-73) are sometimes less than compelling—for example, it is not a given that Hippolytus copies Sextus (which would give a terminus ante quem), rather than the two of them drawing on a common source—and I am inclined to regard Galen’s silence on Sextus as suggesting that he postdated him. But this does not affect the main point, which is that Sextus seems to be specifically responding to a view on the efficacy of logic for medicine that we can find in Galen. Schmitt does not commit herself on whether Sextus has Galen himself as the target, but the view he is opposing is certainly Galenic and probably Galen-inspired. And this makes Sextus’ response a striking example of his intervention in a controversy of his own time. When it comes to philosophy, he generally seems to be interested in eras considerably before his own (which is one reason why pinning down his dates is so hard), but this is clearly not the case when it comes to medicine, at least in this instance.
Sextus ends his discussion of fallacies by saying that he will discuss the topic again later (PH 2.259); his extant works do not include any such discussion. In a brief conclusion, Schmitt speculates that this may have occurred in one of his lost medical works, which he refers to by title (Medical Treatises and Empirical Treatises; M 7.202, M 1.61). Her claim that “there are no other lost philosophical treatises” (96) besides On the Soul (which seems an unlikely venue for such a discussion) is unverifiable; all we can say is that neither he nor anyone else refers to any others. But the suggestion that, if he followed up on his promise, this was in a medical work fits well with the specifically medicine-related concern that animated his treatment of fallacies, according to the argument of chapter 3.
The book is well produced and clearly written. I spotted just a few typos or other small errors: ataraxia instead of tarachê on the bottom line of p.10; “it’s” for “its” in n.42; Atherton 1993, cited in n.88 and elsewhere, missing from the bibliography; “arguable” for “arguably” (p.53); “it” for “if” in the quotation on p.91. The book has a limited scope, and does not pretend otherwise; but it sheds a welcome new light on one significant aspect of Sextus’ treatment of logic, which has implications for how we should regard his skeptical outlook more generally.
Notes
[1] Schmitt has also argued for this in “Sextus versus a Galenic Doctor on Fallacies”, forthcoming in History of Philosophy and Logical Analysis (currently available among the journal’s online Advance Articles).
[2] It is interesting, however, that the examples include reference to terms and procedures characteristic of the Methodic school: constriction, tightening, slackening, and the pivotal significance of the Third Day. Schmitt does not mention this, but it perhaps ties in with Sextus’ flirtation with the Methodic school as closer to skepticism than at least some Empiricists (PH 1.236-241), on which she is judicious (42-43).