I promise to question everything my leaders tell me. I promise to use my critical faculties. I promise to develop my independence of thought. I promise to educate myself so I can make my own judgments.

Where we have strong emotions, we're liable to fool ourselves.

What does it mean for a civilisation to be a million years old? We have had radio telescopes and spaceships for a few decades; our technical civilisation is a few hundred years old ... an advanced civilisation millions of years old is as much beyond us as we are beyond a bushbaby or a macaque

Quickly capping 363 oil well fires in a war zone is impossible. The fires would burn out of control until they put themselves out... The resulting soot might well stretch over all of South Asia... It could be carried around the world... [and] the consequences could be dire. Beneath such a pall sunlight would be dimmed, temperatures lowered and droughts more frequent. Spring and summer frosts may be expected... This endangerment of the food supplies... appears to be likely enough that it should affect the war plans.

Virtually every major technological advance in the history of the human species - back to the invention of stone tools and the domestication of fire - has been ethically ambiguous.

In a complex universe, in a society undergoing unprecedented change, how can we find the truth if we are not willing to question everything and to give a fair hearing to everything?

Our children long for realistic maps of the future that they can be proud of. Where are the cartographers of human purpose?