The positive conception of liberty indeed emphasizes self-mastery. This concept of liberty, often associated with philosophers like Isaiah Berlin, emphasizes not just the absence of external constraints or interference (as in negative liberty), but also the individual's ability to act in accordance with their own rational will, desires, or values.
Self-mastery, in this context, refers to the idea that true freedom involves being in control of oneself, one's actions, and one's destiny. It's about having the capacity to govern oneself and to pursue one's goals and aspirations without being unduly influenced by external forces or internal compulsions.
In positive liberty, self-mastery is often seen as crucial because it enables individuals to realize their potential, to develop their capacities, and to live a life that is truly autonomous and fulfilling. It involves not just being free from external coercion, but also being able to overcome internal obstacles and constraints in order to lead a flourishing and meaningful existence.