The Limits of Epistemology

Markus Gabriel, Alex Englander

• Éditeur: Polity
• Année: 2019
• ISBN:
  9781509525706
• Édition: 1
• Sujet: Filosofia
• Sous-sujet: Epistemologia in filosofia

At the centre of modern epistemology lurks the problem of scepticism: how can we know that the forms of our cognition are compatible with the world? How can we state success conditions for knowledge claims without somehow transcending our discursive and fallible nature as knowers? By distinguishing different forms of scepticism, Markus Gabriel shows how all objective knowledge relies on shared discourses and how the essential corrigibility of knowledge claims is a crucial condition of their objectivity. We should understand scepticism not so much as posing a threat, but as offering a vital lesson about the fallibility of discursive thinking. By heeding this lesson, we can begin to reintegrate the solipsistic subject of modern epistemology back into the community of actual knowers. Taking his cue from Hegel, Wittgenstein and Brandom, Gabriel shows how intentionality as such is a public rather than a private phenomenon. He concedes that the sceptic can prove the necessary finitude of objective knowledge, but denies that this has to lead us into an aporia. Instead, it shows us the limits of the modern project of epistemology. Through an examination of different kinds of sceptical paradoxes, Gabriel not only demonstrates their indispensable role within epistemological theorising, but also argues for the necessary failure of all totalizing knowledge claims. In this way, epistemology, as the discipline that claims knowledge about knowledge, begins to grasp its own fallibility and, as a result, the true nature of its objectivity. The Limits of Epistemology will be of great value to students and scholars of philosophy.

Part I
The Function of Scepticism

1
Negative Dogmatism and Methodological Scepticism

One of the chief lessons of the sciences is that the world diverges substantially from how we tend to view it as naïve observers. Knowledge acquisition and doubt are therefore not merely compatible – they are not even independent phenomena. We need only consider the all too familiar fact that, with every increase in knowledge, we also acquire knowledge of what we do not yet know, of our own ignorance. Indeed, strictly speaking, knowledge in the demanding sense of ‘scientific’ knowledge is unthinkable in the absence of doubts as to whether the world is exactly as it appears to us to be. Departing from our everyday assumptions is a condition of the very possibility of knowledge as such coming into view. Just like anything else human thinkers might investigate, knowledge becomes an object of study only once we have begun to wonder whether and to what extent it actually resembles what we take it to be on the basis of our pre-theoretical assumptions.

As soon as we take even the smallest bite from the fruit of the tree of knowledge, we face the challenge of scepticism: the possibility of knowledge implies the possibility of its impossibility. Knowledge, in short, implies doubt, and the task of alleviating this doubt falls to epistemology.

While scepticism is intimately bound up with the very possibility of each and every attempt to achieve theoretical distance from the world,¹ it represents a particular problem for epistemology. By distancing us from our everyday knowledge ascriptions, epistemology too introduces the possibility of scepticism. But by the same token, it implies the possibility of its own impossibility. After all, epistemology is an inherently self-referential enterprise: it strives for knowledge of knowledge. This makes it peculiarly liable to paradoxes. For if it should turn out that such fundamental epistemic concepts as ‘knowledge’, ‘cognition’, ‘justification’, and so on, imply the possibility of scepticism, then epistemology itself comes under threat. And since it depends upon the viability of these concepts no less than any other theory, epistemology has no choice but to face up to the threat to its own possibility from within.

Equipping ourselves with an explicit understanding of knowledge and doubt is evidently an exercise in reflection, an attempt to seek out stable ground in the face of a recognisable threat. Hence epistemology is always a theory of reflection, a theory which has to give an account of the presuppositions governing its own construction. So much follows from its reflexive character, from the fact that it issues in knowledge claims – knowledge claims about knowledge. And since it is a reaction to scepticism, we can understand scepticism in turn as an enterprise that passes from the destruction of individual knowledge claims to the destruction of knowledge claims as such.

It is therefore not merely an historical coincidence that philosophers in the modern period have deployed Cartesian scepticism as a motivational theory for epistemology, as an ultimately anti-sceptical strategy. This anti-sceptical strategy, first introduced by Descartes himself, amounts to a methodological scepticism, the idea being that we can thematise scepticism as a condition of the possibility of reflection. At the same time, this strategy provokes new, second-order sceptical attacks against which epistemology also has to arm itself.

One of the common moves in the defence of knowledge against the inherent possibility of scepticism is the invocation of immediacy, be it nature (Hume), common sense (Reid, Moore), the everyday (Heidegger), the ordinary (Cavell), and so on. This immediacy, however, is thrown into question not only by specifically epistemological scepticism but by the scepticism implied by the sciences too. The latter continually remind us that some part of the world, or the world as a whole, is not actually as it appears to be from the (alleged) pre-theoretical standpoint of immediacy.² The sciences, that is, exploit the difference between being and appearance no less than philosophy. So if we want to adopt a scientific attitude towards the world, we have to reckon with a potentially considerable difference between how it is and how it appears.

Certain words can convey the impression of picking out a unified phenomenon although, on closer inspection, they in fact do no such thing. Philosophical vocabulary is notoriously guilty in this respect, and positions such as idealism, realism, relativism, and so on, have taken on an often confusing multiplicity of forms throughout the history of philosophy. They can often designate basic options within a certain philosophical subject area, or even fundamental systematic approaches. Indeed, in the eyes of at least some of their representatives, they can sometimes function as descriptions of nothing less than the totality of existence. ‘Scepticism’ provides another example of a word that promises more unity than it in fact delivers. The history of attempts to provide constructive theoretical solutions to all kinds of philosophical problems runs in parallel to the history of attempts to develop corresponding, destructive counter-programmes aimed at demonstrating their impossibility, and the variety of the latter reflects the variety of the former. The conflict between dogmatism and scepticism, which plays out upon philosophy’s ‘battlefield of endless controversies’,³ does not even begin with Plato’s arguments with the Sophists; it already looms large in pre-Socratic philosophy.

Historically, the phenomena that have been assembled under the label ‘scepticism’ have depended primarily upon whichever constructive proposals were on offer at any given time, with the result that scepticism has often been ‘parasitical’ upon dogmatism.⁴ Without any further specification, therefore, ‘scepticism’ is thus just as unclear a term as ‘philosophy’ or ‘science’. Abstractly formulated, ‘scepticism’ can be regarded as a destructive system of assertions formulated with the intention of systematically dislodging some given piece of constructive theorising. Accordingly, the sceptic philosophises from a position of opposition, following a negative programme that presupposes the existence of a positive programme to be used as a foil. This is why the ancient master sceptic Sextus Empiricus, whom we shall encounter again and again throughout this study, determined the ‘activity’ (ἀγωγή) of sceptical philosophising as ‘an ability to set out oppositions among things which appear and are thought of in any way at all’ (δύναμις ἀντιθετικὴ φαινομένων τε καὶ νοουμένων καθ´ οἱονδήποτε τρόπον).⁵ The sceptic, therefore, avowedly pursues a primarily practical (and thus no longer merely destructive) aim insofar as she attempts to finally make good on the salvific promise of ‘tranquillity’ (ἀταραξία), just like the adherents of rival Hellenistic schools. Yet she does so by seeking eudemonia not in contemplation of the eternal, as did Plato and Aristotle, but in the life and customs (νóμοι) of the community. These customs do not admit of a philosophical legitimation but stand for ‘what has to be accepted, the given’,⁶ as they would later for Wittgenstein.

Although one could cite many contemporary philosophers, such as Richard Rorty, Robert Fogelin or Michael Williams, who self-consciously theorise in the tradition of ancient scepticism, none of these authors seriously take up its soteriological dimension. Yet a much more marked and important difference between ancient scepticism and the contemporary scepticism debate (especially as conducted within analytic epistemology) stems from a feature of post-Cartesian philosophy that I have already mentioned, namely that scepticism came to adopt a systematic function within epistemology.

Since Descartes, that is, it has become customary to incorporate scepticism into epistemology’s motivation, a tactic which led Descartes himself to introduce the idea of a constructive scepticism. By a theory’s ‘motivation’, I understand the set of reflections that result in the theory’s execution but cannot themselves be justified through the theory’s (yet to be established) theoretical resources. Motivation is accordingly an operation that conditions a theory, while justification – i.e. the giving of reasons – is already conditioned by a theory. Justification always comes after the fact of motivation.

Descartes made a purely methodological use of scepticism in a way that would prove decisive for modern epistemology. He thereby became (among other things) the precursor of what I shall from now on, following Dietmar Heidemann, label integrative anti-scepticism.⁷ By this term, I mean to pick out any anti-sceptical strategy that regards scepticism as the condition of the intelligibility of the basic question of epistemology: the question of the nature of knowledge. Integrative anti-scepticism sets out from the assumption that the project of modern epistemology can be made comprehensible (intelligible) in the first place – in other words, can be motivated – only given a confrontation with the problem of Cartesian scepticism.

By Cartesian scepticism, I understand the project of formulating sceptical scenarios that have the potential to trigger hyperbolic doubt. The relevant scenarios exercise this potential by showing how the world as a whole could be utterly other than it appears, such that most, or even all, of our beliefs about the world would stand revealed as false.⁸ Clearly, this sense of ‘Cartesian scepticism’ does not designate Descartes’ own ego-logical or theological anti-sceptical strategy, which instead reverses the pattern described above and attempts to deploy sceptical scenarios as a foil for its own constructive programme.

When exploited by an integrative anti-scepticism, Cartesian scepticism functions as a condition of modern epistemological theorising: the strategy in question integrates scepticism into the project of epistemology in the sense that, by making a case for the impossibility of knowledge as conceived by a given philosophical theory, it is scepticism which first opens up the space for epistemology’s basic questions. However, the business of highlighting the precariousness of knowledge serves only as a spur to secure it against the spectre of its impossibility, and thus to overcome scepticism. When it plays this role, the problem of Cartesian scepticism is therefore invoked purely as something to be overcome, specifically by casting it in the form of a methodological scepticism. The latter arises through the confrontation with the possible impossibility of knowledge and goes on to clarify how knowledge is possible after all. In this way, the possibility of knowledge is to be rendered intelligible in and through the thematisation of its potential impossibility.⁹

This broad anti-sceptical strategy makes room for reflection on the conditions of epistemological theorising by assuming from the start t...