 It might be claimed that MacCallum’s framework is less than wholly inclusive of the various possible conceptions of freedom. In particular, it might be said, the concept of self-mastery or self-direction implies a presence of control that is not captured by MacCallum’s explication of freedom as a triadic relation. MacCallum’s triadic relation indicates mere possibilities. If one thinks of freedom as involving self-direction, on the other hand, one has in mind an exercise-concept of freedom as opposed to an opportunity-concept (this distinction comes from C. Taylor 1979). If interpreted as an exercise concept, freedom consists not merely in the possibility of doing certain things (i.e. in the lack of constraints on doing them), but in actually doing certain things in certain ways — for example, in realizing one’s true self or in acting on the basis of rational and well-informed decisions. The idea of freedom as the absence of constraints on the realization of given ends might be criticised as failing to capture this exercise concept of freedom, for the latter concept makes no reference to the absence of constraints.