Some statisticians claim that the surest way to increase the overall correctness of the total set of one' s beliefs is: never change that set, except by rejecting a belief when given adequate evidence against it  However, if this were the only rule one followed, then whenever one were presented with any kind of evidence, one would have to either reject some of one' s beliefs or else leave one' s beliefs unchanged  But then, over time, one could only have fewer and fewer beliefs
Since we need many beliefs in order to survive, the statisticians' claim must be mistaken
presumes, without providing any justification, that the surest way of increasing the overall correctness of the total set of one's beliefs must not hinder one's ability to survive