Unger's Defense of Skepticism

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  • Unger's Defense of SkepticismAuthor(s): Gerald W. BarnesSource: Philosophical Studies: An International Journal for Philosophy in the AnalyticTradition, Vol. 24, No. 2 (Mar., 1973), pp. 119-124Published by: SpringerStable URL: http://www.jstor.org/stable/4318771 .Accessed: 24/06/2014 20:26

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    (Received 6 January, 1972)

    Peter Unger defends' the skeptical thesis that "in the case of every human being, there is hardly anything, if anything at all, which the person knows to be so" (p. 216). He attempts to show that the thesis "deserves, if not our acceptance, at least the suspension of our judgment" (ibid.). I shall argue that his defense appears to be unsound. If it is unsound, then it supplies no reason for hesitating to reject skepticism.

    First let me outline Unger's case. It proceeds from his account of two notions: 'absolute term' and 'relative term' (pp. 202-207). Unger discus- ses mainly the absolute term 'flat' and the correlated relative terms 'bumpy' and 'curved'. Every absolute term has one or more relative terms correlated with it, in the sense that every absolute term can be defined, according to Unger, by means of some one or more relative terms:

    To say that a surface is flat is to say that some things or properties which are matters of degree are not instanced in the surface to any degree at all. Thus, something which is flat is not at all bumpy, and not at all curved. Bumpiness and curvature are matters of degree (p. 203).

    Every absolute term whatever, may be defined, at least partially, by means of certain relative terms. The defining conditions presented by means of the relative terms are negative ones; they say that what the realtive term purports to denote is not present at all, or in the least, where the absolute term correctly applies (p. 206).

    Unger's defense of skepticism goes as follows. With regard to absolute terms other than those denoting something which "divides into discrete units" (p. 210), "fairly reasonable suppositions about the world make it somewhat doubtful that the terms properly apply" (ibid.). With regard to 'flat', for example, it would only be reasonable to assert that there exists a really flat surface if it were reasonable to assert of some surface that "there never is any surface which is flatter than it is" (p. 211). But we simply don't know enough to assert this reasonably of any surface so far observed, even one observed under the highest magnification so far at- tained.

    Philosophical Studies 24 (1973) 119-124. All Rights Reserved Copyright C 1973 by D. Reidel Publishing Company, Dordrecht-Holland

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    The term 'certain' is an absolute term. It can be defined in a variety of ways, by means of such relative terms as 'doubtful', 'uncertain', and 'confident' (p. 209). As with 'flat', so with 'certain': we are virtually never in a position reasonably to assert about anyone, concerning any proposi- tion he entertains, that "there never is anything of which he is more cer- tain" (p. 212), i.e., that what 'doubtful' denotes is "not present at all, or in the least" (p. 206) in him. In other words, one has no grounds for denying that there is nothing or next to nothing of which any person is ever certain. The reasonable course, says Unger, is to "suspend judgment on the matter" (p. 213).

    Next Unger argues that knowing something logically requires being certain of it. This claim plus the earlier claim - that one cannot reason- ably deny that there is nothing or next to nothing of which any person is ever certain - yield the desired skeptical result: we cannot reasonably reject the proposition that everyone knows, at most, next to nothing.

    Unger's defense of skepticism, outlined above, relies upon a premise to this effect: it is virtually never reasonable to assert that what 'doubtful' purports to denote is completely absent from a person's mind with respect to any proposition he entertains. I shall try to show that Unger leaves us without sufficient grounds for believing this premise. Thus, even if valid his defense of skepticism appears to be unsound.

    It will be easier to see that this is so if we begin by considering 'bumpy', rather than 'doubtful'. If it is true of any surface, x, that is flat, then, according to Unger, what 'bumpy' denotes is "not present at all, or in the least" in x (p. 206). Suppose, now, that what 'bumpy' denotes were, roughly speaking, the property of being irregular to the naked eye. In that case, there would be many surfaces which, so far as the negative bumpi- ness requirement goes, qualify as flat, since there are many surfaces which are not "at all, or in the least", irregular to the naked eye. But it is essen- tial to Unger's argument, we have seen, that with regard to certain ab- solute terms, including 'flat', it be a matter of great doubt, at best, whether they ever apply to anything. Thus Unger cannot allow that 'bumpy' denotes the property of being irregular to the naked eye. Nor can 'curved' denote any property defined solely in terms of discriminations by the naked eye. For if 'bumpy' and 'curved' had these denotations, then by Unger's own account, it is plain that many surfaces are flat.

    Assuming that no harm is done by speaking, with Unger, of properties

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    as denoted (rather than connoted) by terms, the natural question here is, what shows what property a term denotes? One plausible reply is that in any given context the denoted property is the property which people generally use the term to denote in that context. Now if this reply is correct without qualification, then there are surely many contexts in which 'bumpy' has something like the denotation which Unger cannot allow. After all, if someone were to complain about having to play on a bumpy tennis court, when the only irregularities of its surface were ones discrim- inable only by means of an electron microscope, his complaint would be hard to make sense of. Or, if we're playing on a really bumpy tennis court, and I stoop down and, with the aid of a magnifying glass, remove a dust mote from it, it could only be as a joke that you would thank me for making the court less bumpy.

    A similar point can be made about many other relative terms, including 'doubtful'. Imagine a non-philosopher, at dinnertime, hard at work trying to repair the oven so that dinner can be cooked. It would only be under quite unusual circumstances that one might suppose the man doubts that he is doing what he takes himself to be doing. Usually he would not doubt it at all, any more than he would doubt that 45 and 56 make 101, or that automobiles exist (Unger's examples). Only someone approaching the case philosophically would be prepared to suggest that the man is not certain of these things, i.e., to deny that "all [my emphasis] doubt is absent in that man's mind" (p. 208); people generally, including the man himself, would not be prepared to say these things.

    Although Unger does not speak directly to the point just made, he does comment more generally on the trustworthiness of ordinary usage. It is possible, he argues (pp. 199-202), for what we ordinarily say about some things to be (unintendedly) false without its falsity having any practical consequences. More importantly, there is a way to demonstrate, in many cases, that what we ordinarily say is (unintendedly) false. Unger claims that there is a 'quite generally applicable" (p. 215) technique for discover- ing unnoticed implications of ordinary usage. It is a matter of "focusing on just those words most directly employed in expressing the concept whose conditions are our object of inquiry" (p. 214). Focusing is done "by suitably juxtaposing certain terms, like 'really' and 'actually', with the terms most in question" (p. 215); and, "more strikingly, we may em- phasize the terms in question" (ibid.).

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    By this technique, "x is the son of y" becomes "x is (really) (actually) the son of y". Thus, speaking informally, there is no harm in saying, for example, that Nelson Rockefeller is the son of John D. Rockefeller, Jr. (Unger's example, pp