Pylyshyn argues that early vision is cognitively impenetrable,
and therefore – contrary to knowledge-based theories of
perception – that perception is noncontinuous with cognition.
Those processes that are included in “early vision,”
however, represent at best only one component of perception, and it is
important that it is not the component with which most knowledge-based
theories are concerned. Pylyshyn's analysis should be taken as a
possible source of refinement of knowledge-based theories of
perception, rather than as a condemnation of them.