at the expense of sounding like a total geek, I suggest looking at characters puzzling like John Locke in the light of 'character alignments' that frp players would already be familiar with- a sweet & sour combo of 'chaotic good' and 'lawful neutral' is how I see the Locke character- at least at the present state of things, given that neither such alignments nor Losties have much to do with rigid and unchanging typifications.
might be of interest:
Alignment (Dungeons & Dragons) - Wikipedia, the free encyclopedia