of being conscious is merely an error in perception, held by brains which evolved to hold erroneous and
incomplete models of their own internal workings, just as they hold erroneous and incomplete models of
their own bodies and of the external world.[77][78]
The main criticisms of eliminative materialism and illusionism hinge on the counterintuitive nature of the
view. Arguments of this form are called Moorean Arguments. A Moorean argument seeks to undermine
the conclusion of an argument by asserting that the negation of that conclusion is more certain than the
premises of the argument.[79]
The roots of the Moorean Argument against illusionism extend back to Augustine of Hippo who stated
that he could not be deceived regarding his own existence, since the very act of being deceived secures
the existence of a being there to be the recipient of that deception.[note 1][80]
In the Early-Modern era, these arguments were repopularized by René Descartes, who coined the now
famous phrase "Je pense, donc je suis" ("I think, therefore I am").[81] Descartes argued that even if he
was maximally deceived (because, for example, an evil demon was manipulating all his senses) he would
still know with certainty that his mind exists, because the state of being deceived requires a mind as a
prerequisite.[82]
This same general argumentative structure is still in use today. For example, in 2002 David Chalmers
published an explicitly Moorean argument against illusionism. The argument goes like this: The reality of
consciousness is more certain than any theoretical commitments (to, for example, physicalism) that may
be motivating the illusionist to deny the existence of consciousness. The reason for this is because we
have direct "acquaintance" with consciousness, but we do not have direct acquaintance with anything else
(including anything that could inform our beliefs in consciousness being an illusion). In other words:
consciousness can be known directly, so the reality of consciousness is more certain than any
philosophical or scientific theory that says otherwise.[83] Chalmers concludes that "there is little doubt
that something like the Moorean argument is the reason that most people reject illusionism and many find
it crazy."[84]
Eliminative materialism and illusionism have been the subject of criticism within the popular press. One
highly cited example comes from the philosopher Galen Strawson who wrote an article in the New York
Review of Books titled "The Consciousness Deniers". In it, Strawson describes illusionism as the "silliest
claim ever made", next to which "every known religious belief is only a little less sensible than the belief
that the grass is green."[85] Another notable example comes from Christof Koch (a neuroscientist and one
of the leading proponents of Integrated Information Theory) in his popular science book The Feeling of
Life Itself. In the early pages of the book, Koch describes eliminativism as the "metaphysical counterpart
to Cotard's syndrome, a psychiatric condition in which patients deny being alive."[86] Koch takes the
prevalence of eliminativism as evidence that "much of twentieth-century analytic philosophy has gone to
the dogs".[87]
Type-B Materialism, also known as Weak Reductionism or A Posteriori Physicalism, is the view that the
hard problem stems from human psychology, and is therefore not indicative of a genuine ontological gap
between consciousness and the physical world.[43] Like Type-A Materialists, Type-B Materialists are
Criticisms
Type-B Materialism