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are irrelevant; relative to his strategies of enquiry, they might as
well have been false, and this state of affairs he cannot want. So in
the description of the state which, with due caution, we can say that
A wants to arrive at, namely
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(v) A truly believes that p, and his belief has the property E,
we can read E as
. . . appropriately produced in a way such that beliefs produced in that
way are generally true,
where appropriately means that the truth of the belief is not acci-
dental relative to what it is about the way of its production which
makes that a generally reliable way. Taken in this way, (v) surely is
sufficient for knowledge. So starting merely from the idea of pursu-
ing truth in a non-magical world, and so of the truth-seeker s using
methods of enquiry, we do arrive at the conclusion that the search
for truth is the search for knowledge. The notion of knowledge,
however, is very unambitiously used. In particular, it does not
entail any kind of certainty or indubitability. Descartes s step to
that is what will now concern us.
Sticking just to generally reliable methods, A will almost cer-
tainly have some false beliefs. If he reflects, he can know that he
will almost certainly have some false beliefs, but, very obviously,
he will not know which they are if he did, he would not have
them as beliefs. So the methods are not, and are known to A not to
be, perfect, in the sense of yielding only true beliefs. But they may
well be the best that A can employ there may be no way in which
A can significantly raise the truth-ratio among his beliefs, at least
within the context of objectives which are just as important to him.
There may be no method which radically excludes falsehood, and
still yields any beliefs at all, or at least any non-trivial beliefs. Of
course, A is committed to being correct, not to being omniscient: he
wants (ideally) all his beliefs to be true, not (even ideally) to believe
all truths. But he certainly wants to have some beliefs; and he wants
to have them on matters of concern to him.
A typical situation is that the truth-ratio could be somewhat
improved without giving up any classes of beliefs altogether, but
that the cost of doing so would be too high, relative to other activ-
ities (including other activities of enquiry). A might be able fruit-
fully to enquire further into the reliability of a given method, or
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whether its application on a given occasion was appropriate, but
such activities take time and effort, which it may not be sensible to
spend in any given case; while it is impossible to spend them in
every case. In actual life, investment of effort into enquiry turns
importantly on what is at stake: we check the petrol tank more
thoroughly before a drive across the Sahara than before a drive
across town. Moreover, there is the important point for both prac-
tical and for more theoretical enquiries, that each of us is one
enquirer among others, and there is a division of epistemic labour,
so that what it is rational (in this economic or decision-theoretical
sense) for Y to investigate in detail, it is rational for Z to take on Y s
say-so.
All these are reasons why A in his everyday circumstances either
cannot increase his truth-ratio or should not regard it as rational to
try. But for Descartes s enquiry none of these considerations
applies. Descartes very carefully presents himself as now in a situ-
ation where he is devoted solely to enquiry, and as having, so long
as this exercise continues, no other interests. He stresses repeat-
edly, as in the passage from the Discourse quoted above (p. 21), that
his Doubt , his instrument of reflective enquiry, is not to be
brought into practical matters: equally, no values drawn from those
matters affect the enquiry. The strategic rationality which guides
the enquiry is to be entirely internal to it: no questions about what,
in a general economic sense, is worth enquiring into or checking,
are, within the confines of this exercise, to count. Moreover, not
only is he solely devoted to enquiry, but he is the sole enquirer. He
is to embody rational enquiry, so to speak, to the exclusion of
everything and everybody else. With the exercise defined in these
terms, then, so long as one remains within it, most of the consider-
ations that rationally weigh with everyday A against his trying to
raise his truth-ratio, merely lapse.
There remains the issue we mentioned first, of the extent to
which he can raise the truth-ratio and still retain any, or any non-
trivial, beliefs. The point here is that Descartes just does not know
in advance of his enquiry whether or not there are substantial
beliefs to be had by methods which do not bring false beliefs as
well. But if this is uncertain, then in so far as truth and (we have
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seen) knowledge are his object, it is worth while trying to find out.
There are, importantly, two different levels at which this can be
said to be worthwhile. Let us call the perspective from which all
strategic considerations are laid aside except those internal to
enquiry and the search for truth, the perspective of the Pure
Enquirer; our original primitive truth-gatherer, A, may be said to
turn into the Pure Enquirer when he loses all interests other than
his interest in knowledge. Now within the perspective of the Pure
Enquirer, it is trivially true that the exercise of trying to find
methods which maximize the truth-ratio is a worthwhile exercise,
for within that perspective there is no worth but the worth of
truth-pursual. But there is of course a different question, addressed
to Descartes or any other actual man, of the worthwhileness of
adopting for a while the perspective of the Pure Enquirer, and this
question requires an answer from outside that perspective, in terms
of a wider worthwhileness to human life.
Deeper reasons for adopting this project or, alternatively, for
rejecting it, we shall come back to at the end of this chapter. For the
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