[Kepler] preferred the hard truth to his dearest illusions, and that is the heart of science.
Carl SaganTeller contended, not implausibly, that hydrogen bombs keep the peace, or at least prevent thermonuclear war, because the consequences of warfare between nuclear powers are now too dangerous. We haven't had a nuclear war yet, have we? But all such arguments assume that the nuclear-armed nations are and always will be, without exception, rational actors, and that bouts of anger and revenge and madness will never overtake their leaders (or military and secret police officers in charge of nuclear weapons). In the century of Hitler and Stalin, this seems ingenuous.
Carl SaganSince World War II, Japan has spawned enormous numbers of new religions featuring the supernatural.... In Thailand, diseases are treated with pills manufactured from pulverized sacred Scripture. Witches are today being burned in South Africa.... The worldwide TM [Transcendental Meditation] organization has an estimated valuation of $3 billion. For a fee, they promise to make you invisible, to enable you to fly.
Carl SaganThe significance of our lives and our fragile planet is then determined only by our own wisdom and courage. We are the custodians of life's meaning. We long for a Parent to care for us, to forgive us our errors, to save us from our childish mistakes. But knowledge is preferable to ignorance. Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal.
Carl Sagan