  This paper critically assesses the anti-functionalist stance on consciousness
adopted by certain advocates of integrated information theory (IIT), a
corollary of which is that human-level artificial intelligence implemented on
conventional computing hardware is necessarily not conscious. The critique
draws on variations of a well-known gradual neuronal replacement thought
experiment, as well as bringing out tensions in IIT's treatment of
self-knowledge. The aim, though, is neither to reject IIT outright nor to
champion functionalism in particular. Rather, it is suggested that both ideas
have something to offer a scientific understanding of consciousness, as long as
they are not dressed up as solutions to illusory metaphysical problems. As for
human-level AI, we must await its development before we can decide whether or
not to ascribe consciousness to it.
