The more we learn of the true nature of non-human animals, especially those with complex brains and corresponding complex social behavior, the more ethical concerns are raised regarding their use in the service of man—whether this be in entertainment, as "pets," for food, in research laboratories, or any of the other uses to which we subject them.

Through a Window: My Thirty Years with the Chimpanzees of Gombe (2000), p. 245.