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