 Many of the objections to these views are just specific applications of objections to reliabilism, externalism, and teleological theories more generally. For instance, clairvoyance objections (BonJour 1980) aim to show that reliability is not sufficient for prima facie justification, and new evil demon arguments (Lehrer &amp; Cohen 1983) insist that reliability is not necessary  (see the entry on reliabilist epistemology).  Teleological theories face the additional problem of the Swampman (Davidson 1987), who is a randomly occurring (therefore, lacking in any biological functions) molecular duplicate of a normal person; intuitively he seems to have justified perceptual beliefs, although this cannot be accounted for in terms of proper function.