A thing which is autotelic is described as "having a purpose in and not apart from itself".
Mihaly Csikszentmihalyi describes people who are internally driven, and who as such may exhibit a sense of purpose and curiosity, as autotelic. This is different from being externally driven, in which case things such as comfort, money, power, or fame are the motivating force.
There is already noun translation, autotélisme, but is there an adjective for it?