Does Every Genuine Philosophy Have a Skeptical Side?
Michael N. Forster
As some readers may already know, I have spent a number of years now mining Hegel’s writings for insights into skepticism. Among those that I have identified and broadly endorsed, the following three perhaps stand out in importance: (1) Hegel argues convincingly that ancient skepticism and modern skepticism are sharply different in character (ancient skepticism being typified by the “equipollence” method, modern skepticism by the “veil of perception” problem), and that as a result ancient skepticism is philosophically superior to modern, in particular because free of an essential dogmatism, and resulting vulnerability to skepticism, which afflict the latter.1 (2) Hegel argues, in opposition to Kant and other people influenced by him such as G.E. Schulze, who conceive ancient skepticism as limited in the scope of its attack, that ancient skepticism is on the contrary a radical position which attacks virtually all beliefs. This interpretive dispute has recently been replayed by Myles Burnyeat and Michael Frede respectively. I have argued that it is the radical Hegel-Burnyeat reading of ancient skepticism rather than the moderate Kant-Frede reading that is more exegetically correct.2 (3) Hegel argues, again in opposition to Kant and others influenced by him, that such a radical form of ancient skepticism is moreover philosophically viable. In particular, he argues that it can viably attack even judgments of subjective experience and logical principles. I have argued that on this point too Hegel is correct.3
In this article I would like to identify and defend a fourth important Hegelian insight into skepticism: the thesis he articulates in his seminal 1802 essay The Relation of Skepticism to Philosophy that every genuine philosophy has a skeptical side – or, as he puts it, “that skepticism itself is most intimately one with every true philosophy . . . that a true philosophy necessarily itself . . . has a negative side.”4 *
In order to appropriate and defend this Hegelian thesis, I will first need to clarify and disambiguate it in certain ways, though. In particular, the following three points should be noted.
First, Hegel’s thesis in his 1802 essay is often concerned with “true philosophy” in the very narrow sense of “philosophy that is true” – which would restrict the bearing of the thesis to just his own philosophy and a few alleged anticipations thereof by favored predecessors such as Plato. On the other hand, in the very context of the remarks that I just quoted, Hegel rejects the idea that philosophy should be equated with dogmatism and implies that it also includes a broad range of skeptically minded thinkers, among them not only Plato but also certain poets, Zeno, Xenophanes, and Democritus.5 And at other points in the essay he identifies Pyrrho and the older set of Pyrrhonian tropes as examples of philosophy too.6 So there are also good textual grounds for construing “true philosophy” in his thesis in the broader sense, not of “philosophy that is true,” but of something more like “genuine philosophy” (whether true or not). While the former, narrow sense of his thesis is undeniably present in the essay, I find it philosophically unattractive, and shall therefore simply set it aside here. It is the latter, broad sense of the thesis that seems to me to have good prospects of being correct, and which interests me here.
Second, somewhat surprisingly, Hegel in the 1802 essay identifies as the paradigm of “skepticism” the second half of Plato’s Parmenides – which Hegel interprets as a destructive dialectic both preparatory and integral to Plato’s positive philosophy (very much as Hegel’s own destructively dialectical Logic was at this period of his career both preparatory and integral to his own positive philosophy). However, as I already mentioned, Hegel in the essay also credits a much broader range of skeptically minded thinkers as representatives of “skepticism,” including Zeno, Xenophanes, Democritus, and especially the Pyrrhonists. In short, he often seems ready to count as “skepticism” virtually any systematic negative intellectual assault on received beliefs or claims to knowledge.7 I shall not here be interested in Hegel’s thesis insofar as it concerns only “skepticism” in the narrow sense of a Platonic-Hegelian destructive dialectic. Nor, for that matter, shall I be interested in it insofar as it concerns only “skepticism” in the much less idiosyncratically narrow sense of Pyrrhonism, or Pyrrhonism and Academic skepticism. Rather, I shall be interested in it insofar as it concerns “skepticism” in the broader sense that I just attributed to Hegel (which includes, but is not restricted to, Platonic-Hegelian dialectic, Pyrrhonism, and Academic skepticism). If one prefers to use an alternative name for this broader range of positions one might perhaps call them subversive epistemologies.
Third, concerning Plato’s role as the star example that Hegel adduces in support of his thesis: I think that he is actually a good example, but not necessarily in quite the way that Hegel supposes. Hegel reads the second half of Plato’s Parmenides as a systematic dialectical destruction of pre-philosophical presuppositions which leads to a monistic Platonic philosophical standpoint (very much on the model of Hegel’s own early Logic and its relation to his own monistic philosophy). That this is the real character of Plato’s Parmenides is quite questionable, however. Nonetheless, Hegel’s more generic idea that Plato’s philosophical standpoint was largely a response to skepticism (qua subversive epistemology) remains very plausible indeed. Recall, for example, the account that Plato puts in the mouth of his philosophical representative Socrates in the Phaedo, where Socrates explains his recourse to the theory of forms in terms of the need to avoid the common “misology” of supposing that equally convincing arguments can be supplied on both sides of any issue and that everything is in flux, and in terms of the need to find a solution to the demoralizing impact that a series of paradoxes had had on his earlier commonsense and scientific outlook.8 And recall also Aristotle’s similar explanation of Plato’s theory of forms, according to which it was originally motivated by Plato’s desire to escape the conception of Heraclitus and Cratylus that everything is in flux, so that scientific knowledge is impossible.9
In short, what really interests me here is Hegel’s general thesis that every genuine philosophy has a skeptical side (in a broad sense of the word “skeptical” in which it connotes subversive epistemology) either because the philosophy is itself skeptical or because it is a response to skepticism – a thesis which Hegel in particular, and with considerable generic plausibility, illustrates by means of the example of Plato.
This thesis seems to me interesting in the context of a very basic question that any philosopher surely needs to ask himself at some point: What makes philosophy philosophy? In particular, what distinguishes it from such closely related fields as, for example, religion or natural science?
In raising this question, I do not mean to imply that it must be possible to provide a strict definition – a set of non-trivial, essential necessary and sufficient conditions – for any general term, such as “philosophy,” on pain of otherwise failing properly to understand it. The (originally Socratic, Platonic, and Aristotelian) notion that it must always be possible to supply such a definition for a general term is a mistake, and has long since been exposed as such (especially by the later Wittgenstein).10 Perhaps “philosophy” is instead a “family resemblance” concept (as Morris Weitz has plausibly argued that “art” is, and Alastair Fowler that “literature” is).11 Even after that mistake has been set aside, it still seems reasonable to expect that we should be able to provide some fairly informative criteria for properly calling something “philosophy” – as opposed to, say, “religion” or “natural science.” So what might these be?
Subject matter does not look like a promising answer. Philosophers as a group discuss virtually anything and everything. And accordingly, specific areas of the discipline largely overlap in subject matter with other disciplines: Philosophy of religion and religion itself (or theology) mostly treat of the same subject matter. So do philosophy of science and natural science. And this sort of overlap occurs in many other areas of philosophy as well – for example, moral philosophy overlaps with morality itself; philosophy of mind with psychology; epistemology with cognitive psychology; philosophy of mathematics with mathematics itself.
Nor does approach look like a promising answer. For paradigmatic philosophers routinely disagree in deep ways about what the approach of their discipline should be. A sort of science of man (the Sophists, J.S. Mill)? A sort of handmaiden to natural science (Bacon and the positivists)? A description of the most general concepts and principles, those that apply to reality as such (Aristotle and the metaphysical tradition)? Inquiry about inquiry (John Passmore)?12 . . .
Nor does method look like a promising answer. For here again paradigmatic philosophers routinely disagree in deep ways about what their discipline’s method should be. A destructive elenchus applied to ethical claims (Socrates)? A more constructive and broader dialectic (Plato, Hegel)? A destructive balancing of opposed arguments leading to suspension of judgment (the Pyrrhonists)? A geometrical method for expounding the one substance (Spinoza)? A sort of empirical inquiry concerning the mind (Hume)? A transcendental investigation into the conditions of the possibility of experience (Kant)? Phenomenological description (Husserl)? Conceptual analysis (Russell)? Linguistic analysis (Wittgenstein, Austin)? . . .
What I want to suggest is that Hegel’s thesis provides a much more promising answer to our question: It is a criterion (a necessary and sufficient condition) of something’s being philosophy – as opposed to, say, religion or natural science – that it have a skeptical side, i.e. either itself be a form of skepticism or else be deeply concerned to answer skepticism.
Two clarifications of this suggestion may be in order before we proceed further. First, in making it I mean, like Hegel himself in certain moods, to employ a very broad conception of “skepticism” that covers not only skepticism strictly so called – say, Pyrrhonism with its distinctive skeptical methods, such as the equipollence method – but also a considerably wider range of systematic negative intellectual assaults on received beliefs or claims to knowledge. For example, in an ancient context this would also include Xenophanes’ attack on divine inspiration and on the senses as sources of knowledge; Parmenides’ attack on the coherence of the concept of not-being (and on further concepts and beliefs which depend on it); Zeno’s paradoxes of motion; the Sophists’ antilogic; Socrates’ elenchus; and so on. In other words, my suggestion concerns “skepticism” in the sense of subversive epistemologies.
Second, I offer this suggestion neither as a simple discovery of the real essence of philosophy nor as a mere stipulative definition, but rather – a third possibility that lies somewhere between the two, though closer to the former than to the latter – as a sort of “rational reconstruction” of what philosophy consists in. To borrow (and slightly modify) a helpful description of such a project that John Passmore has already given: “The test of whether a ‘rational reconstruction’ of philosophy is a reasonable one is whether it provides us with a method of demarcating philosophy from other forms of inquiry, even if in order to do so it is obliged to exclude much that ordinarily passes as philosophy [Passmore might usefully have added: or to reclassify some of what ordinarily passes as something else as philosophy. – M.N.F.]. The rational reconstructor [though] is not so much prescribing as drawing attention to a difference.”13
A clue that there may be something to this Hegelian thesis can already be found in the earliest origins of the term “philosophy.” Diogenes Laertius (in a passage confirmed by Clement) reports the following on that subject: “The first to use the term philosophy, and to call himself a philosopher [lit. ‘lover of wisdom’] was Pythagoras; for, he said, no man is wise but god alone. Heraclides of Pontus, in his De Mortua, makes him say this . . . All too quickly the study was called wisdom and its professor a sage, to denote his attainment of mental perfection; while the student who took it up was a philosopher.”14 According to this credible report, then, the term “philosophy” initially connoted a certain sort of deeply skeptical stance, only later coming to connote aspirations to overcome skepticism by attaining knowledge.
This double use of the term to connote either a sort of skepticism or a sort of anti-skepticism aimed at attaining knowledge is, I think, still visible in Plato. On the one hand (and this is a fact that has usually been overlooked), Plato’s Socrates, especially in early dialogues, often still seems to be using the term in something very much like the earlier of the two senses distinguished by Diogenes (rather than in the later sense of a positive search for knowledge). For example, in the early dialogue Euthydemus Socrates is happy to allow that the Sophists Euthydemus and Dionysodorus are philosophers (304d-307c), even though he clearly thinks that they care nothing at all for real wisdom or truth, only for displaying their cleverness in verbal combat. Here the term seems to connote a certain sort of negative activity: the activity, shared in common by these Sophists and Socrates himself, of conducting a type of refutatory conversation (which Plato in both cases calls elenchein). This may well be Socrates’ idea when he describes himself as “philosophizing” in the Apology as well. For example, in the phrase there “I should spend my life philosophizing and cross-questioning myself and the others” (28e), he seems almost to equate philosophizing with cross-questioning oneself and others (cf. 23c-d, 29c-d; also Lesser Hippias, 363a; Gorgias, 486a-d). In addition, Socrates’ use of the term in the Apology to describe himself seems to connote his own (and other people’s) lack of knowledge, and his awareness of this ignorance. For it is in the context of discussing precisely this that he first applies the term to himself at 23d, and his introduction of the term there seems intended to mark a sharp contrast between himself and the Sophists whom he has just been discussing as people who by contrast do claim to have knowledge (see especially 19e-20c). Moreover, Lysis, 218a and Symposium, 203e-204a both explicitly show him using the term to connote a condition in which a person lacks knowledge and is also aware of the fact. In addition, and echoing a further central aspect of the earlier usage of the term reported by Diogenes, Socrates’ introduction of the term at Apology, 23d occurs immediately after he has drawn a sharp contrast between such human ignorance and divine knowledge (23a-b). And similarly, at Phaedrus, 278d he says that “the epithet ‘wise’ . . . befits god alone, but the name ‘philosopher’ or something of the sort would be more fitting and modest [for a man].” In short, Plato’s dialogues, especially his early ones, seem to contain a usage of the term “philosophy” that corresponds very closely to the earlier of the two usages distinguished by Diogenes: a usage that (rather than connoting any positive search for knowledge) connotes the skeptical stance of conducting refutatory conversations which display the refuter’s recognition of human ignorance (including his own), in contradistinction to divine knowledge.
On the other hand, and much more famously, Plato’s dialogues, especially his middle and late ones, also contain a usage of the term “philosophy” that answers very closely to Diogenes’s second, later sense: that of a positive search for knowledge in the face of skeptical difficulties. (See, for example, Lysis, 218a; Phaedo, 61d ff.; Republic, 485a ff.; Symposium, 203e–204a; Theaetetus, 173c–174b.)
How well does the Hegelian thesis fare when considered in the light of what philosophers actually do, though?
Given that, as I am conceiving it, it involves rational reconstruction, its success does not require that every so-called philosopher or philosophy should conform to the proposed criterion of being either skeptical or anti-skeptical. However, it is important that paradigmatic philosophers and philosophy should do so. So how does the thesis fare in this light?
It seems to me that our existing ways of classifying thinkers as “philosophers” or “non-philosophers,” and their ideas as “philosophy” or “non-philosophy,” within an ancient context conform pretty well to this thesis. For example, we usually classify as “philosophy” both the broadly skeptical positions of Xenophanes, the Eleatics, the Sophists, Socrates, the Pyrrhonian skeptics, and the Academic skeptics and the broadly anti-skeptical positions of Plato and the Stoics. But we do not normally classify as “philosophy” the neither skeptical nor anti-skeptical religion of Homer or the neither skeptical nor anti-skeptical natural science of Hippocrates.15
There is a problem case, however: Aristotle. Aristotle is certainly a paradigmatic philosopher, if ever there was one. Yet he can easily seem, and indeed has seemed to many, to be quite unconcerned with skepticism. As one recent author has put it, “Aristotle, throughout all his writings, is . . . notorious in balking at skeptical questions. He just does not take the skeptic seriously at all.”16 If Aristotle really were as free of concerns about skepticism as this implies, then that fact would constitute a pretty powerful argument against the Hegelian thesis that skepticism plays an essential role in philosophy. I would therefore like to devote much of the remainder of this article to taking a closer look at the case of Aristotle. My goal here will not, of course, be to support the Hegelian thesis by doing induction from a single example! Rather, it will be to defend it by defusing what is perhaps the most threatening-looking candidate counterexample to it.17
A good place for that defusing to begin may be with Aristotle’s famous account in the Metaphysics of what, in his view, originally motivated, and continues to motivate, philosophers: “It is through wonder that men now begin and originally began to philosophize; wondering in the first place at obvious perplexities [ta procheira tôn aporôn].”18 Compare with this Aristotle’s more specific account (already mentioned above) that Plato’s theory of forms had its origins in his perplexity at the doctrine of Heraclitus and Cratylus that everything is in flux, and that scientific knowledge is therefore impossible –19 a conception of the motive for philosophy with which Aristotle himself expresses sympathy at one point.20
In accordance with this general position, it is surely at least clear on reflection that much of Aristotle’s philosophy is concerned to answer skepticism in the broad sense that I distinguished earlier: skepticism qua systematic negative intellectual assaults on received beliefs or claims to knowledge (i.e. subversive epistemology).
Let me briefly indicate a few of the ways in which this is so. First, much of Metaphysics, book Gamma is devoted to refuting forms of skepticism about the law of contradiction (including Heraclitus’s form of it), and about the law of excluded middle. Second, book Gamma in addition continues a project already begun by Plato’s Theaetetus of refuting the subversive epistemology of Protagoras, namely his relativism; for example, it replays Plato’s self-refutation charge against Protagoras’s relativism.21 Third, book Gamma also attempts to refute a broader range of skeptical ideas – including, for example, Xeniades’ (and perhaps also Gorgias’s) thesis that every claim is false.22 Fourth, in the Physics and elsewhere Aristotle attempts to refute Parmenides’ case for the incoherence of the concept of not-being – indeed, achieving this goal seems to be one of Aristotle’s main motives for introducing his fundamental concept of matter (in contradistinction to form).23 Fifth, Aristotle devotes much of the Physics to refuting Zeno’s paradoxes of motion – by, inter alia, sharply distinguishing between infinite divisibility and infinite extension; insisting that space’s infinite divisibility is matched by that of time; and claiming that spatial and temporal points exist only potentially, not actually.24 Sixth, On Sophistical Refutations is largely devoted to the task of identifying and defusing a whole range of fallacies on which the Sophists and others had relied in making various sorts of skeptical arguments. Seventh, in the Metaphysics Aristotle implies that the reason why Socrates failed to achieve the positive goal of arriving at satisfactory definitions in ethics, instead getting bogged down in elenctic refutations and achieving no answer of his own, was that he lacked Aristotle’s own technique of dialectic.25 So Aristotle apparently conceives the sort of dialectical inquiry into ethical questions that he himself undertakes in the Nicomachean Ethics to be (among other things) a way of defusing Socratic elenchus.
In short, a concern to rebut various types of skepticism in the broad sense is a pervasive feature of Aristotle’s philosophy.
In addition, though, and perhaps more surprisingly, it also seems plausible to see Aristotle as anticipating and addressing the sorts of challenges to belief and knowledge that would later typify skepticism in the narrow sense, Pyrrhonism.26
My case for saying this will fall into two parts. The first part is heavily indebted to some recent secondary literature on the subject, including Jonathan Barnes’s essay “An Aristotelian Way with Scepticism” and especially Anthony Long’s essay “Aristotle and the History of Greek Skepticism.”27 The second part is significantly indebted to Hegel.
Here is the first part of my case. Perhaps the most striking example of Aristotle anticipating and responding to Pyrrhonism’s challenges concerns the Pyrrhonian tropes of Agrippa, or more precisely the central subset of them that has recently been dubbed the “Agrippan trilemma”:28 infinite regress, vicious circularity, or dogmatic presupposition (and consequent vulnerability to a contrary dogmatic presupposition).29 At Posterior Analytics, 72b-73a Aristotle in effect (if not entirely in intention) does the following three things: (1) he draws attention to a cruder proto-form of the trilemma’s problem that had already been advanced by certain predecessors; (2) he refines it into the fuller and subtler form that we later find in the Pyrrhonists; and (3) he proposes a response to it.30 The cruder proto-form of the problem that Aristotle finds before him – a proto-form probably due to Antisthenes – says that knowledge is impossible because undemonstrated presuppositions cannot constitute knowledge and the attempt to avoid them leads to infinite regress.31 Aristotle’s refinement of that problem comes in his rejection of a proposal some other people had apparently already made that the solution to it lay in circular demonstration. Aristotle argues that such circularity would be vicious – in particular, because genuine demonstration requires that the premises be better known than the conclusion, and such an epistemic asymmetry obviously cannot hold in two directions at once.32 This rejection of circular demonstration in effect leaves the reader with the full Agrippan trilemma (indeed, it seems almost certain to me that Agrippa got it from just this source). However, Aristotle also proposes a solution to the problem. His solution is that it is a mistake to assume that undemonstrated presuppositions cannot constitute knowledge: “We, however, hold that not all knowledge is demonstrative: the knowledge of immediate premises is not by demonstration . . . Indeed we hold not only that scientific knowledge is possible, but that there is a definite first principle of knowledge by which we recognize ultimate truths/definitions [tous horous]” (Aristotle here means the faculty of nous).33 Aristotle invokes this position that it is sometimes perfectly proper to accept presuppositions without a demonstration, and that it is a mistake always to expect a demonstration, in many other places as well (e.g. Metaphysics, 1006a, 1011a).