Yeah, I have settled on introspection, it works very well for that. I would say study of psychology and Neuroscience, but this can be a very mixed bag, and can mislead as much as illuminate. (Think the dogmatic psychologist from the 80's, refusing to discuss high-functioning autism?)

I suppose this is because people are also drawn to knowledge for reasons of power. If you adopt it for that reason, it becomes quite rigid; loosing its ability to adapt over time. I'm not sure why this is the case, just something I have observed.

Knowing yourself can only be done with a very soft touch!