Knowledge and Skepticism

Marjorie Clay

• Publisher: Routledge
• Year: 2019
• ISBN:
  9780429710131
• Edition: 1
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

This book presents the characteristic of philosophical writing in the theory of knowledge covering the major themes: skepticism, externalism, reliabilism, probability, and justification. It also analyses epistemology from both historical and contemporary perspective.

1
A ‘Doxastic Practice’ Approach to Epistemology

William P. Alston

I

How can we determine which epistemic principles are correct, valid, or adequate? One way to motivate concern with this issue is to consider controversial principles. What does it take to be justified in perceptual beliefs about the physical environment? Can I be justified in believing that there is a tree in front of me just by virtue of that belief’s stemming, in a certain way, from a certain kind of visual experience? Or do I also need reasons, in the form of what I know about my visual experience or about the circumstances of that perception? How do we tell what set of conditions is sufficient for the justification of such beliefs? Another and more usual way to motivate concern with the issue is to raise the specter of skepticism. Why suppose that any set of conditions we can realize is sufficient? No matter what experiences and beliefs I have, couldn’t they have been produced directly by an omnipotent being that sees to it that there is no physical world at all and that all my perceptual beliefs are false? That being the case, why should we suppose that our sensory experience justifies us in holding any beliefs about the physical world?

As the above paragraph suggests, the epistemic principles I will be thinking of lay down conditions under which one is justified in holding beliefs of a certain kind. I shall be using the justification of perceptual beliefs as my chief example. For a more specific focus, you can take your favorite principle of justification for perceptual beliefs. Following my own injunction, I will focus on my favorite, which runs as follows.

I. — S is prima facie justified in perceptually believing that x is P iff S has the kind of sensory experience that would normally be taken as x appearing to S as P, and S’s belief that x is P stems from that experience in the normal way.

If we were interested in this principle for its own sake, much more would have to be done by way of elucidation. Here I will just say that the justification is only prima facie because it can be overridden by sufficient reason to suppose that x is not P or that the experience in this case is not sufficiently indicative of x’s being P. I present this particular principle only to have something fairly definite to work with. Our concerns in this paper lie elsewhere. Nothing will hang on the specific character of I.

What it takes to be justified in accepting a principle of justification depends on what justification is. I have discussed this matter at some length elsewhere.¹ Here I must confine myself to laying it down that epistemic justification is essentially “truth conducive.” That is, to be justified in believing that p is to believe that p in such a way that it is at least quite likely that one’s belief is true.² One way of developing this idea is to say that S is justified in believing that p only if that belief was acquired in a reliable manner. This is not to identify justification with reliability; the ‘only if principle leaves room for other necessary conditions. I shall be thinking of justification as subject to a “reliability constraint.” If this is distasteful to you, you can take the chapter as having to do with the epistemic status of principles of reliability, and leave justification out of the picture altogether.

So to determine which of the competing principles of the justification of perceptual beliefs is correct, if any, we have to determine, inter alia, which of them, if any, specify a reliable mode of belief-formation. And to show, against the skeptic, that perception is a source of justified belief (knowledge), we have to show that some mode of forming perceptual beliefs is reliable. But how to do this? Let’s take a particular principle that specifies a mode of perceptual belief-formation, e.g., I., and consider what it would take to show that the mode so specified is reliable. The main difficulty is that there seems to be no otherwise effective way of showing this that does not depend on sense perception for some or most of its premises. Take the popular argument that sense perception proves its veridicality by the fact that when we trust our senses and build up systems of belief on that basis we have remarkable success in predicting and controlling the course of events. That sounds like a strong argument until we ask how we know that we have been successful at prediction and control. The answer is, obviously, that we know this only by relying on sense perception. Somebody has to take a look to see whether what we predicted did come to pass and whether our attempts at control were successful. Though I have no time to argue the point here, I suggest that any argument for the reliability of perception that is not otherwise disqualified will at some point(s) rely on perception itself. I shall assume this in what follows.³

What I have just been pointing to is a certain kind of circularity, one that consists in assuming the reliability of a source of belief in arguing for the reliability of that source. That assumption does not appear as a premise in the argument, but it is only by making the assumption that we consider ourselves entitled to use some or all of the premises. Let’s call this epistemic circularity. In a recent essay I argue that, contrary to what one might suppose, epistemic circularity does not render an aigument useless for justifying or establishing its conclusion.⁴ Provided that I can be justified in certain perceptual beliefs without already being justified in supposing sense perception to be reliable,⁵ I can legitimately use perceptual beliefs in an argument for the reliability of sense perception.

However, this is not the end of the matter. What I take myself to have shown in “Epistemic Circularity” is that epistemic circularity does not prevent one from showing, on the basis of empirical premises that are ultimately based on sense perception, that sense perception is reliable. But whether one actually does succeed in this depends on one’s being justified in those perceptual premises, and that in turn, according to our assumptions about justification, depends on sense perception being a reliable source of belief. In other words, if (and only if) sense perception is reliable, we can show it to be reliable.⁶ But how can we cancel out that if?

Here is another way of posing the problem. If we are entitled to use beliefs from a certain source in showing that source to be reliable, then any source can be validated. If all else fails, we can simply use each belief twice over, once as testee and once as tester. Consider crystal ball gazing. Gazing into the crystal ball, the seer makes a series of pronouncements: p, q, r, s … Is this a reliable mode of belief-formation? Yes. That can be shown as follows. The gazer forms the belief that p, and, using the same procedure, ascertains that p. By running through a series of beliefs in this way, we discover that the accuracy of this mode of belief-formationis 100%! If some of the beliefs contradict others, that will reduce the accuracy somewhat, but in the absence of massive internal contradiction the percentage of verified beliefs will still be quite high. Thus, if we allow the use of mode of belief-formation M to determine whether the beliefs formed by M are true, M is sure to get a clean bill of health. But a line of argument that will validate any mode of belief-formation, no matter how irresponsible, is not what we are looking for. We want, and need, something much more discriminating. Hence the fact that the reliability of sense perception can be established by relying on sense perception does not solve our problem.⁷

II

This is where the “doxastic practice” approach of the title comes into the picture. For help on the problem of the first section, I am going to look to two philosophers separated by almost two hundred years, Thomas Reid and Ludwig Wittgenstein. Both were centrally concerned with our problem, albeit in somewhat different guises. Since within the limits of this paper I am simply drawing inspiration from these figures, mining their work for ideas that I will develop in my own way, I will not attempt to present their views in anything like an adequate fashion.

First Wittgenstein. In On Certaintf⁸ Wittgenstein is concerned with the epistemic status of propositions of the sort G. E. Moore highlighted in his “Defence of Common Sense” and “Proof of an External World” — such propositions as This is my hand, The earth has existed for many years, and There are people in this room. The gist of Wittgenstein’s position is that the acceptance of such propositions is partially constitutive of participation in one or another fundamental “language-game.”⁹ To doubt or question such a proposition is to question the whole language-game of which it is a keystone. There is no provision within that language-game for raising such doubts. In fact, there is no provision within the language-game for justifying such beliefs, exhibiting evidence for them, or showing that we know such matters, as Moore tried to do. Hence we cannot even say that we know or are certain of such matters. They are too fundamental for that By accepting these and other “anchors” of the game we are thereby enabled to question, doubt, establish, refute, or justify less fundamental propositions. Nor can we step outside the language-game in which they figure as anchors and critically assess them from some other perspective. They have their meaning only within the game in which they play a foundational role; we cannot give sense to any dealings with them outside this context.

Thus, if we ask why we should suppose that some particular language-game is a reliable source of belief, Wittgenstein responds by denying the meaningfulness of the question. The concept of a trans-or inter-language-game dimension of truth or falsity is ruled out on verificationist grounds. We can address issues of truth and falsity only within a language-game, by employing its criteria and procedures to investigate issues that are within its scope. Hence there is no room for raising and answering questions about the reliability of a language-game as a whole. To be sure, language-games are not sacrosanct or fixed in cement. It is conceivable that they should be abandoned and new ones arise in their place. But even if we should have some choice in the matter, something that Wittgenstein seems to deny, the issue would be a practical, not a theoretical, one. It would be a choice as to what sort of activity to engage in, not a choice as to whether some proposition is true or false.¹⁰ The foundation of the language-game is action, not intuition, belief, or reasoning.

Applying this to the problem raised in section I, Wittgenstein’s view is that no sensible question can be raised concerning the reliability of the language-game that involves forming beliefs on the basis of sense-perception. There is no perspective from which the question can be intelligibly raised. This is a sphere of activity in which we are deeply involved; “this language-game is played.”¹¹ We could try to opt out, but even if, per impossible, we could do so, that would have been a practical decision; and what possible reason could we have for such a decision? If, as is in fact the case, we continue to be a whole-hearted participant, we are simply engaged in (perhaps unconscious) duplicity in pretending to question, doubt, or justify the practice.

Now I do not accept for a moment Wittgenstein’s verificationist restrictions on what assertions, questions, and doubts are intelligible. There is no time here for an attack on verificationism. I will simply testify that I can perfectly well understand the propositions that sense perception is (is not) reliable, that physical objects do (do not) exist, and that the earth has (has not) been in existence for more than a year, whether or not I or anyone else has any idea of how to go about determining whether one of these propositions is true. This confidence reflects a realistic concept of truth, on which a proposition’s being true is not a matter of anyone’s actual or possible epistemic position vis-à-vis the proposition. Hence I cannot accept Wittgenstein’s solution to skepticism about perception and his answer to the question of the epistemic status of epistemic principles, the solution that seeks to dissolve the problem by undercutting the supposition that it can be meaningfully posed.

But then how can I look to Wittgenstein for inspiration? I shall explain. First a terminological note. Because I am concentrating on ways of forming and critically evaluating beliefs, I shall use the teim ‘doxastic practice,’ instead of ‘language-game.’ The term ‘practice’ will be misleading if it is taken to be restricted to voluntary activity; for I do not take belief-formation to be voluntary. I am using ‘practice’ in such a way that it stretches over, e.g., psychological processes such as perception, thought, fantasy, and belief-formation, as well as voluntary action. A doxastic practice can be thought of as a system or constellation of dispositions or habits, or, to use a currently fashionable term, mechanisms, each of which yields a belief as output that is related in a certain way to an “input.” The sense perceptual doxastic practice (hereinafter SPP) is a constellation of habits of forming beliefs in a certain way on the basis of inputs that consist of sense experiences.

Let me now set out the basic features of the view of doxastic practices I have arrived at, partly inspired by Wittgenstein. Some of these features are not stressed by Wittgenstein and some are only hinted at. But I believe that all of them are in the spirit of his approach.

1. We engage in a plurality of doxastic practices, each with its own sources of belief, its own conditions of justification, its own fundamental beliefs, and, in some cases, its own subject matter, its own conceptual framework, and its own repertoire of possible “overriders.” There is no one unique source of justification or knowledge, such as Descartes and many others have dreamed of. However, this point needs to be handled carefully. What it is natural to count as distinct doxastic practices are by no means wholly independent We have to rely on the output of memory and reasoning for the overriders of perceptual beliefs. Apart from what is stored in memory, and used in reasoning, concerning the physical world and our perceptual interactions therewith, we would have nothing to go on in determining when sensory deliverances are and are not to be trusted. Reasoning is beholden to other belief-forming practices for its premises. We can, of course, reason from the output of previous reasoning, but somewhere back along the line we must have reasoned from beliefs otherwise obtained.¹² Thus we must avoid any suggestion that these practices can be engaged in separately.

We need to distinguish between what we may call “generational” and “transformational” practices. Generational practices produce beliefs from non-doxastic inputs; transformational practices transform belief inputs into belief outputs.¹³ Generational practices could be used without reliance on other practices, as in forming perceptual beliefs without any provision for a second, “censor” stage that filters out some beliefs as incompatible with what we already firmly believe. This would be a more primitive kind of practice than we actually have in mature human beings, but it is possible, and may well be actual in very young children and lower animals. Moreover, our mature “introspective” practice is of this independent sort if, as seems likely, beliefs about one’s current conscious states do not regularly pass any test of compatibility with what we believe otherwise. Transformational practices, on the other hand, cannot be carried on in any form without dependence on other practices. We have to acquire beliefs from some other source in order to get reasoning started.

Each of the generational practices has its own distinctive subject matter and conceptual scheme. SPP is a practice of forming beliefs about the current physical environment of the subject, using the common sense “physical object” conceptual scheme. Introspective practice is a practice of forming beliefs about the subject’s own current conscious states, using the “conscious state” conceptual scheme, whereas beliefs formed by reasoning and by memory can be about anything whatever and can use any concepts whatever.

Then is there anything common to all doxastic practices, other than the fact that each is a regular systematic way of forming beliefs? Yes. In the initial statement I said that each practice has its own “sources of belief’ and its own “conditions of justification.” These are two sides of the same coin. We may take the former as our fundamental criterion for distinctness of doxastic practices. The practices we have distinguished differ in the kind of belief-forming “mechanism” involved....

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Dedication
• Contents
• Introduction
• 1 A ‘Doxastic Practice’ Approach to Epistemology
• 2 Understanding Human Knowledge in General
• 3 The Skeptic’s Appeal
• 4 Précis and Update of Epistemology and Cognition
• 5 The Need to Know
• 6 Convention, Confirmation, and Credibility
• 7 Probability in the Theory of Knowledge
• 8 Knowledge Reconsidered
• 9 Knowledge Representation and the Interrogative Model of Inquiry
• About the Contributors