This paper presents a functional genealogy of essentialist authenticity. The essentialist account maintains that authenticity is the result of discovering and realizing one’s ‘true self’. The genealogy shows that essentialist authenticity can serve the function of supporting continuity in one’s individual characteristics. A genealogy of essentialist authenticity is not only methodologically interesting as the first functional genealogy of a contingent concept. It can also deepen the functional understanding of authenticity used in neuroethics, provide a possible explanation for the prevalence of (...) the idea of an essentialist true self and justify the use of the ideal of authenticity. First, essentialist authenticity is defined and explained through the work of Jean-Jacques Rousseau. Second, a general need to have steady characteristics is derived from basic human practices. Third, circumstances that make it more challenging to steady oneself are identified and shown to have become more prevalent in the age of modernity when the ideal of authenticity emerged. Finally, it is shown how essentialist authenticity helps to steady the self. (shrink)