Self-awareness early philosophical discussion of self-awareness is that of John Locke. Locke was apparently influenced by René Descartes' statement normally translated 'I think, therefore I am' ("Cogito ergo sum"). In chapter XXVII "On Identity and Diversity" of Locke's "An Essay Concerning Human Understanding" (1689) he conceptualized consciousness as the repeated self-identification of oneself through which moral responsibility could be attributed to the subject—and therefore punishment and guiltiness justified, as critics such as Nietzsche would point out, affirming "...the psychology of conscience is not 'the voice of God in man'; it is the instinct of cruelty ... expressed, for the first time,
Cogito, ergo sum in the former case, and an objective thinker in the latter. He argues, first, that it is impossible to make sense of "there is thinking" without relativizing it to "something." However, this something cannot be Cartesian egos, because it is impossible to differentiate objectively between things just on the basis of the pure content of consciousness. The obvious problem is that, through introspection, or our experience of consciousness, we have no way of moving to conclude the existence of any third-personal fact, to conceive of which would require something above and beyond just the purely subjective contents of the mind.