Extinction is the rule. Survival is the exception.

Human beings grew up in forests; we have a natural affinity for them. How lovely a tree is, straining toward the sky.

Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you.

It's a lazy Saturday afternoon, there's a couple lying naked in bed reading Encyclopediea Brittannica to each other, and arguing about whether the Andromeda Galaxy is more 'numinous' than the Ressurection. Do they know how to have a good time, or don't they?

Absolute certainty will always elude us. We will always be mired in error. The most each generation can hope for is to reduce the error. . . .

The absence of evidence is not the evidence of absence.

Some 5 billion years from now, there will be a last perfect day on Earth... then the sun will begin to die, life will be extinguished, the oceans will boil and evaporate away.