A human being: an ingenious assembly of portable plumbing.
—Christopher Morley
Human beings are the only animals of which I am thoroughly and cravenly afraid.
—George Bernard Shaw
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
Machines are for answers; humans are for questions.
—Kevin Kelly