A rule of thumb with humor; if you worry that you might be going too far, you have already not gone far enough. If everybody laughs, you have failed.

Very often the test of one's allegiance to a cause or to a people is precisely the willingness to stay the course when things are boring, to run the risk of repeating an old argument just one more time, or of going one more round with a hostile or (much worse) indifferent audience.

If you think all this is going on, all these gigantic fields of gravity and light with you in mind, then you really do have a self-centredness problem.

One has children in the expectation of dying before them. In fact, you want to make damn sure you die before them, just as you plant a tree or build a house knowing, hoping that it will outlive you. That's how the human species has done as well as it has.

We owe a huge debt to Galileo for emancipating us all from the stupid belief in an Earth-centered or man-centered (let alone God-centered) system. He quite literally taught us our place and allowed us to go on to make extraordinary advances in knowledge.

It is exactly the fear of revenge that motivates the deepest crimes, from the killing of the enemy's children lest they grow up to play their own part, to the erasure of the enemy's graveyards and holy places so that his hated name can be forgotten.

"Objective" means that, in a confrontation with the evidence, you would be willing to change your own mind.