Maybe it's a little early. Maybe the time is not quite yet. But those other worlds - promising untold opportunities - beckon. Silently, they orbit the Sun, waiting.

We on Earth have just awakened to the great oceans of space and time from which we have emerged.

Human history can be viewed as a slowly dawning awareness that we are members of a larger group Groups of people from divergent ethnic and cultural backgrounds working in some sense together [is] surely a humanizing and character building experience. If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth.

Books tap the wisdom of our species -- the greatest minds, the best teachers -- from all over the world and from all our history. And they're patient.

When permitted to listen to alternative opinions and engage in substantive debate, people have been known to change their minds. It can happen.

History is full of people who out of fear, or ignorance, or lust for power has destroyed knowledge of immeasurable value which truly belongs to us all. We must not let it happen again.

Teller 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.