 According to this theory we are in some sense in direct contact with the external world when we seem to be perceiving it, and not merely in direct contact with some mediating representation in our mind, such as a sense-datum or an image, which may or may not correspond to external reality.The psychologist J.J. Gibson, referred to above, became an advocate of the philosophical theory of direct realism.Hallucinatory experiences reported by sane people do not pose any new problem in principle for the theory of direct realism, other than that posed already by the more widely discussed hallucinations reported by people in a state of psychosis or under other abnormal conditions such as sensory deprivation.