Self-authorship has been established as the basis of an influential liberal principle of legislation and public policy. Being the author of one’s own life is a significant component of one’s own well-being, and therefore is better understood from the viewpoint of the person whose life it is. However, most philosophical accounts, including Raz’s conception of self-authorship, rely on general and abstract principles rather than specific, individual psychological properties of the person whose life it is. We elaborate on the principles of (...) self-authorship on the basis of self-determination theory, an empirically based psychological theory that has been at the forefront of the study of autonomy and self-authorship for more than 45 years. Our account transcends distinctions between positive and negative freedom and attempts to pinpoint the exact properties of self-authorship within the psychological processes of intrinsic motivation and internalization. If a primary objective of public policy is to support self-authorship, then it should be devised on the basis of how intrinsic motivation and internalization can be properly supported. Self-determination theory identifies three basic psychological needs: autonomy, competence, and relatedness. The satisfaction of these needs is associated with the support and growth of intrinsic tendencies and the advancement of well-being. Through this analysis, we can properly evaluate the significance of rationality, basic goods, and the availability of options to self-authorship. Implications for law and policy are discussed with an emphasis on legal paternalism and what many theorists call “liberal perfectionism,” that is, the non-coercive support and promotion of the good life. (shrink)