What we take ourselves to be doing when we think about what is the case or how we should act is something that cannot be reconciled with a reductive naturalism, for reasons distinct from those that entail the irreducibility of consciousness. It is not merely the subjectivity of thought but its capacity to transcend subjectivity and to discover what is objectively the case that presents a problem....Thought and reasoning are correct or incorrect in virtue of something independent of the thinker's beliefs, and even independent of the community of thinkers to which he belongs. (p. 71)
Thomas NagelMaterialism is incomplete even as a theory of the physical world, since the physical world includes conscious organisms among its most striking occupants.
Thomas Nagelfundamentally an organism has conscious mental states if and only if there is something that it is like to be that organism--something it is like for the organism.
Thomas Nagel