A sharp distinction between humans and "animals" is essential if we are to bend them to… — Carl Sagan

A sharp distinction between humans and "animals" is essential if we are to bend them to our will, make them work for us, wear them, eat them—without any disquieting tinges of guilt or regret... Humans—who enslave, castrate, experiment on, and fillet other animals—have had an understandable penchant for pretending that animals do not feel pain... It is unseemly of us, who often behave so unfeelingly toward other animals, to contend that only humans can suffer... The behavior of other animals, especially the chimps and bonobos, renders such pretensions specious. They are just too much like us.