The problem of human nature, the Augustinian quaestio mihi factus sum … seems unanswerable in both its individual psychological sense and its general philosophical sense. It is highly unlikely that we, who can know, determine, and define the natural essences of all things surrounding us which we are not, should ever be able to do the same for ourselves—this would be like jumping over our own shadows. Moreover, nothing entitles us to assume that man has a nature or essence in the same sense as other things. In other words, if we have a nature or essence, then surely only a god could know and define it, and the first prerequisite would be that he be able to speak about a "who" as though it were a "what." The perplexity is that the modes of human cognition applicable to things with "natural" qualities, including ourselves to the limited extent that we are specimens of the most highly developed species of organic life, fail us when we raise the question: And who are we?
—HANNAH ARENDT