For me, I think it's a mixture of idealism, concern and compassion for the humankind and generally towards life on earth. I've also always had this semi-neurotic need to fully understand any phenomenom or issue I'm interested in. Idealism is what precedes experience; cynicism is what follows. It's quite easy to get cynical and think nothing will change, that there's nothing one individual can do about anything, but things always change, one way or the other. Yes, what anyone can accomplish by themselves is extremely limited, but another way of looking at it is that it's the individuals that have ALL the power, we collectively are the only ones that can make any change occur. You can of course choose ignorance and negligence, bury your head in the sand and hope bad things go away, but personally I just can't do that. How this is possible without having good Christian morals is still beyond me.