A worry about testimony akin to Hume's emerges for Alston's position if we consider
someone who is not a practitioner of CMP or any of its rivals. Assuming that the outputs
of CMP have prima facie justification for its practitioners, the question then arises
whether such justification can be transferred to those who are not among its practitioners
by means of testimony. Alston accepts the following sufficient condition for justification
by testimony: I believe that p justifiably if (1) someone else, X, is justified in believing
that p; (2) X tells me that p; and (3) I am justified in supposing that X is justified in
believing that p. He argues that there is no good reason to deny that this sufficient
condition for justification via testimony can be satisfied in the case of someone whose
only basis for belief in the outputs of CMP is the testimony of its practitioners. However,
William J. Wainwright (2000) has proposed a serious objection to this conclusion. He
points out that my reasons for thinking that the beliefs to which the practitioners of CMP
testify are justified will be very similar to reasons I have for thinking that the beliefs to
which the practitioners of some rivals, for instance, Buddhist mystical practice (BMP),
testify are justified. But, by hypothesis, the outputs and associated background beliefs of
CMP and BMP are massively incompatible.
end p.398
Wainwright draws the following conclusion: “Hence, whatever reasons I have for
assenting to the products of BMP are reasons against assenting to the products of CMP
(and vice versa). And this seems to be a good reason for withholding assent altogether.
The existence of incompatible mystical practices seems to provide the religiously
uncommitted with a rather decisive reason for suspending judgment” (220). In cases of
this sort, conflicting testimonies really do seem to cancel one another out.
I also think Alston's analogical argument only warrants a conclusion that is weaker than
the one he actually draws from it. Let us return briefly to the hypothetical example of
competing Aristotelian, Cartesian, and Whiteheadian sensory perceptual practices. I do
not deny that it would be rational for me to sit tight with my Aristotelian practice in the
imagined situation. But it seems to me that there is also another rational course open to
me because I think it would be rational for me to revise my Aristotelian practice from
within and work toward the social establishment of the revised practice. There is, after
all, a precedent for making revisions in sensory perceptual practice to be found in the way
people have responded to learning from modern science that such things as phenomenal
colors, odors, tastes, and sounds are not mind-independent features of physical reality. At
least when they are being careful, people who have learned this lesson regard the outputs
of sensory perceptual practice as beliefs about how the physical environment appears to
them rather than beliefs about how it is in itself, independent of them. So I have the
option of revising my Aristotelian practice in a Kantian direction.
Suppose it occurs to me that a plausible explanation of the success of the diverse sensory
practices in the imagined situation is the hypothesis that each of the socially established
practices is reliable with respect to the appearances physical reality presents to its
practitioners, but none is reliable with respect to how physical reality is in itself.
Motivated by this thought and the desire to improve the reliability of my sensory practice,
I modify it so that it maps sensory inputs onto doxastic outputs about the appearances
physical reality presents to me but not about how it really is independent of me. And I do