December 1, 2010

PAGE 22

According to the theory, we need to qualify rather than deny the absolute character of knowledge. We should view knowledge as absolute, reactive to certain standards (Dretske, 1981 and Cohen, 1988). That is to say, in order to know a proposition, our evidence need not eliminate all the alternatives to that preposition, rather for us, that we can know our evidence eliminates al the relevant alternatives, where the set of relevant alternatives (a proper subset of the set of all alternatives) is determined by some standard. Moreover, according to the relevant alternatives view, and the standards determining that of the alternatives is raised by the sceptic are not relevant. If this is correct, then the fact that our evidence cannot eliminate the sceptics alternative does not lead to a sceptical result. For knowledge requires only the elimination of the relevant alternatives, so the relevant alternative view preserves in both strands in our thinking about knowledge. Knowledge is an absolute concept, but because the absoluteness is relative to a standard, we can know many things.


The interesting thesis that counts as a causal theory of justification (in the meaning of causal theory intended here) are that: A belief is justified in case it was produced by a type of process that is globally reliable, that is, its propensity to produce true beliefs-that can be defined (to a good approximation) As the proportion of the beliefs it produces (or would produce) that is true  is sufficiently great.

This proposal will be adequately specified only when we are told (i) how much of the causal history of a belief counts as part of the process that produced it, (ii) which of the many types to which the process belongs is the type for purposes of assessing its reliability, and (iii) relative to why the world or worlds are the reliability of the process type to be assessed  the actual world, the closet worlds containing the case being considered, or something else? Let us look at the answers suggested by Goldman, the leading proponent of a reliabilist account of justification.

(1) Goldman (1979, 1986) takes the relevant belief producing process to include only the proximate causes internal to the believer. So, for instance, when believing that the telephone was ringing the process that produced the belief, for purposes of assessing reliability, includes just the causal chain of neural events from the stimulus in my ears inward and other brain states on which the production of the belief depended: It does not include any events in the telephone, or the sound waves travelling between it and my ears, or any earlier decisions made, that were responsible for being within hearing distance of the telephone at that time. It does seem intuitively plausible of a belief depends should be restricted to internal oneness proximate to the belief. Why? Goldman does not tell us. One answer that some philosophers might give is that it is because a beliefs being justified at a given time can depend only on facts directly accessible to the believers awareness at that time (for, if a believer ought to holds only beliefs that are justified, she can tell at any given time what beliefs would then be justified for her). However, this cannot be Goldmans answer because he wishes to include in the relevantly process neural events that are not directly accessible to consciousness.

(2) Once the reliabilist has told us how to delimit the process producing a belief, he needs to tell us which of the many types to which it belongs is the relevant type. Coincide, for example, the process that produces your believing that you see a book before you. One very broad type to which that process belongs would be specified by coming to a belief as to something one perceives as a result of activation of the nerve endings in some of ones sense-organs. A constricted type, in which that unvarying processes belong would be specified by coming to a belief as to what one sees as a result of activation of the nerve endings in ones retinas. A still narrower type would be given by inserting in the last specification a description of a particular pattern of activation of the retinas particular cells. Which of these or other types to which the token process belongs is the relevant type for determining whether the type of process that produced your belief is reliable?

If we select a type that is too broad, as having the same degree of justification various beliefs that intuitively seem to have different degrees of justification. Thus the broadest type we specified for your belief that you see a book before you apply also to perceptual beliefs where the object seen is far away and seen only briefly is less justified. On the other hand, is we are allowed to select a type that is as narrow as we please, then we make it out that an obviously unjustified but true belief is produced by a reliable type of process. For example, suppose I see a blurred shape through the fog far in a field and unjustifiedly, but correctly, believe that it is a sheep: If we include enough details about my retinal image is specifying te type of the visual process that produced that belief, we can specify a type is likely to have only that one instanced and is therefore 100 percent reliable. Goldman conjectures (1986) that the relevant process type is the narrowest type that is casually operative. Presumably, a feature of the process producing beliefs were causally operatives in producing it just in case some alternative feature instead, but it would not have led to that belief. We need to say some here rather than any, because, for example, when I see an oak or maple tree, the particular like-minded material bodies of my retinal image is causally clear towards the worked in producing my belief that what is seen as a tree, even though there are alternative shapes, for example, oak or maples, ones that would have produced the same belief.

(3) Should the justification of a belief in a hypothetical, non-actual example turn on the reliability of the belief-producing process in the possible world of the example? That leads to the implausible result in that in a world run by a Cartesian demon-a powerful being who causes the other inhabitants of the world to have rich and careened sets of perceptual and memory impressions that are all illusory the perceptual and memory beliefs of the other inhabitants are all unjustified, for they are produced by processes that are, in that world, quite unreliable. If we say instead that it is the reliability of the processes in the actual world that matters, we get the equally undesired result that if the actual world is a demon world then our perceptual and memory beliefs are all unjustified.

Goldmans solution (1986) is that the reliability of the process types is to be gauged by their performance in normal worlds, that is, worlds consistent with our general beliefs about the world  . . . about the sorts of objects, events and changes that occur in it. This gives the intuitively right results for the problem cases just considered, but indicate by inference an implausible proportion of making compensations for alternative tending toward justification. If there are people whose general beliefs about the world are very different from mine, then there may, on this account, be beliefs that I can correctly regard as justified (ones produced by processes that are reliable in what I take to be a normal world) but that they can correctly regard as not justified.

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