 Towards identifying the function of consciousness, Nozick distinguishes seven increasing gradations of awareness that correlate with and explain graduated capacity to fit behavior to aspects of situations.Nozick's last book, "Invariances", pursues a theme begun in "The Nature of Rationality" that he calls the genealogy of ethics, in contrast to a justificatory account.It identifies coordination of activity for mutual benefit as the evolutionary source and function of ethics.