 Campbell’s opening move against this argument is to reject Hume’s premiss that we believe testimony solely on the basis of experience. For, according to Campbell, there is in all of us a natural tendency to believe other people. This is not a learned response based on repeated experience but an innate disposition. In practice this principle of credulity is gradually finessed in the light of experience. Once testimony is placed before us it becomes the default position, something that is true unless or until proved false, not false unless or until proved true. The credence we give to testimony is much like the credence we give to memory. It is the default position as regards beliefs about the past, even though in the light of experience we might withhold belief from some of its deliverances.