Absolute version of materialism and physicalism with respect to mental entities and mental vocabulary, according to which our common-sense understanding of the mind (what eliminativists call folk psychology) is not a viable theory on which to base scientific investigation: behaviour and experience can only be adequately explained on the biological level. Therefore, no coherent neural basis will be found for everyday folk psychological concepts (such as belief, desire and intention, for they are illusory and therefore do not have any consistent neurological substrate. Eliminative materialists therefore believe that consciousness does not exist except as an epiphenomenon of brain function and some believe that the concept will eventually be eliminated as neuroscience progresses.