INHERENTLY GOOD?!

Now that i have finished the book i am positively sure that NO body can be inherently good! Why?? Jack was always a stubborn stuck up little brat to start with but the killing and the blood, Piggy was nice because that is his personality and he can change but decides not to. Everybody in the novel were good to start with but the killing the blood and the obsession for power is why they are evil with no heart and acting MEAN to the TRIBE!! I am good and bad because its is the situation that makes you react because for example i am nice and i like to be a nice person but when people are mean and grumpy to me i just FLIP OFF and become a bad person!! That is not a really good scene but everyone has a moment in life where the BAD COMES OUT!!!