The sturdiest pillars of human morality are compassion and a sense of justice.

When it comes to social interaction, the chimpanzees appear to be just as intelligent as we are.

Bonobo studies started in the '70s and came to fruition in the '80s. Then in the '90s, all of a sudden, boom, they ended because of the warfare in the Congo. It was really bad for the bonobo and ironic that people with their warfare were preventing us from studying the hippies of the primate world.

I've argued that many of what philosophers call moral sentiments can be seen in other species. In chimpanzees and other animals, you see examples of sympathy, empathy, reciprocity, a willingness to follow social rules. Dogs are a good example of a species that have and obey social rules; that's why we like them so much, even though they're large carnivores.

We would much rather blame nature for what we don't like in ourselves than credit it for what we do like.

Studies of reconciliation in primates have demonstrated that if the relationship value increases between two parties they are more willing to make peace.

We start out postulating sharp boundaries, such as between humans and apes, or between apes and monkeys, but are in fact dealing with sand castles that lose much of their structure when the sea of knowledge washes over them. They turn into hills, leveled ever more, until we are back to where evolutionary theory always leads us: a gently sloping beach.