man is both good and evil. and we are capable of such great good deeds as we are great evil deeds.
we decide on the things we do base on our morality - whatever our mind, our heart, our whole being dictates. morality is different for each of us. what is good for you, may be evil for me, vice-versa. no one is perfectly evil or perfectly good. even the saints were the most ungodly people.
what makes good or evil? it's a popularity vote. whatever the collective morality deem good or evil is what is.
on response to aero, there is an eye that looks inside and an eye that looks outside. while we have great tendencies to be selfish, we can be selfless. i see people risk their lives for others without even thinking.