On humans

Humans -- who enslave, castrate, experiment on, and fillet other animals --
have had an understandable penchant for pretending animals do not feel
pain. A sharp distinction between humans and "animals" is essential if we
are to bend them to our will, wear them, eat them -- without any
disquieting tinges of guilt or regret. -Carl Sagan, astronomer and author
(1934-1996) & Ann Druyan, author (1949- ) [Shadows of Forgotten Ancestors,
1993]