It has actually been suggested that warfare may have been the principle evolutionary pressure that created the huge gap between the human brain and that of our closest living relatives, the anthropoid apes. Whole groups of hominids with inferior brains could not win wars and were therefore exterminated.

To me, trees are living beings and they have their own sort of personalities.

We, as humans, have actually developed a sense of social responsibility. We have gone beyond our basic instincts.

We're the ones who can make a difference. If we lead lives where we consciously leave the lightest possible ecological footprints, if we buy the things that are ethical for us to buy and don't buy the things that are not, we can change the world overnight.

Anyone who tries to improve the lives of animals invariably comes in for criticism from those who believe such efforts are misplaced in a world of suffering humanity.

I see that within each human being there are two extremes: there's the loving, the passionate, altruistic side that has evolved with us, and then there's the violent, brutal side that has evolved with us. The question for each individual is: which side is going to come out on top?

Being evil is something that only humans are capable of.