The paper will take up several criteria which are considered necessary by various accounts of personal autonomy. These criteria are authenticity, synchronous consistency, and diachronic continuity. I will examine the theory of “volitional necessities” put forward by Harry Frankfurt and show that this account, despite its intention to meet these criteria, fails to do so in several respects. I then consider two alternative suggestions. The first of these, which still refers closely to Frankfurt’s account, also seems to fail because it ascribes to the involved person a too passive role in the process of defining her fundamental commitments. The second proposal, however, which is based on Charles Taylor’s theory of persons as “self-interpreting animals”, turns out to be more promising, for it seems to be able to avoid the flaws of both radical existentialist accounts, on the one hand, and Frankfurt’s too restrictive theory of “volitional necessities”, on the other hand. According to this proposal, the definition of our most fundamental commitments, which are at the same time the essential features of our selves, come about through a process of both discovering and constituing. This account can therefore be considered as an attempt to show a third way between radical existentialism and equally radical essential nature accounts.