As a philosophical rationalist, Nagel believes that a proper understanding of the place of mental properties in nature will involve a revolution in our understanding of both the physical and the mental, and that this is a reasonable prospect that people can anticipate in the near future. A plausible science of the mind will give an account of the stuff that underpins mental and physical properties in such a way that people will simply be able to see that it necessitates both of these aspects. Now, it seems to people that the mental and the physical are irreducibly distinct but that is not a metaphysical insight, or an acknowledgment of an irreducible explanatory gap, but simply where people are at their present stage of understanding.