establishment in each case reflects a culturally generated way of reinforcing socially
desirable attitudes and practices, reinforcing these by inculcating a sense of the presence
of Supreme Reality and a way of thinking about it” (1991, 276). And that view in turn, he
allows, would imply that the justificatory efficacy of all these mystical practices had been
altogether dissipated.
According to Alston, things are not this bad for CMP because it derives self-support from
the way promises it represents God as making are fulfilled in the spiritual lives of its
practitioners, fulfilled in growth in sanctity, joy, love, and other fruits of the spirit. The
rivals of CMP also enjoy self-support derived from spiritual fruits in the lives of their
practitioners. Yet self-support does not wholly offset the negative epistemic
consequences of religious diversity. Alston holds that “it can hardly be denied that the
fact of religious diversity reduces the rationality of engaging in CMP (for one who is
aware of the diversity) below what it would be if this problem did not exist” (1991, 275).
So religious diversity reduces but does not altogether dissipate the justificatory efficacy
of CMP and its similarly situated competitors. But does it reduce it to such a degree that
it is not rational for one who is aware of it to engage in CMP?
Alston thinks not. His main argument proceeds by way of an analogy between the actual
diversity of mystical perceptual practices and a merely hypothetical diversity of sensory
perceptual practices. He asks us to imagine there being a
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plurality of sensory perceptual doxastic practices as diverse as the actual forms of
mystical practice of which we are aware. As he fleshes out his story, “suppose that in
certain cultures there were a well established Cartesian' practice of seeing what is visually perceived as an indefinitely extended medium that is more or less concentrated at various points, rather than, as in ourAristotelian' practice, as made up of more or less
discrete objects scattered about in space” (1991, 273). We are also to imagine in other
cultures an established “Whiteheadian” practice in which the visual field is seen as made
up of momentary events growing out of each other in a continuous process. Further,
suppose that all these practices were roughly equal in the fruits they produced: each
served its practitioners well in their dealings with the environment and had associated
with it a developed physical science. Finally, imagine that in this situation we were as
firmly wedded to our Aristotelian practice as we are in fact, yet could find no
independent grounds on which to argue effectively that it yields more accurate beliefs
than the Cartesian or Whiteheadian alternatives. It seems to Alston that “in the absence of
an external reason for supposing that one of the competing practices is more accurate
than my own, the only rational course for me is to sit tight with the practice of which I
am a master and which serves me so well in guiding my activity in the world” (274, my
emphasis). But the hypothetical situation we have imagined is parallel in relevant
respects to the actual situation of the practitioners of CMP. Hence, by parity of reasoning,
the only rational thing for them to do is to stick with it and, more generally, to continue to
accept and operate in accordance with the background system of Christian beliefs. And,
again by parity of reasoning, the only rational course for practitioners of similarly
situated rivals to CMP is to sit tight with their mystical practices and the associated
systems of background beliefs.