I suppose it depends on what that theory of history entails. It's hard to deny that some individuals are more influential than others, but that doesn't mean the great ones are sufficient to account for all historical changes. The founders of cults that grow into cultures are often forgotten, too, as others take credit for their ideas. So you can be artistically great while languishing in obscurity.

I'm writing something currently that distinguishes between what may be the essence of transhumanism, and the sci-fi trappings and speculations.