Science is a way of thinking much more than it is a body of knowledge.

[...] I try not to think with my gut. If I'm serious about understanding the world, thinking with anything besides my brain, as tempting as that might be, is likely to get me into trouble. Really, it's okay to reserve judgement until the evidence is in.

The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.

He didn't want to believe. He wanted to know.

You mustn't think of the Universe as a wilderness. It hasn't been that for billions of years," he said. "Think of it more as... ..cultivated.

What distinguishes our species is thought. The cerebral cortex is in a way a liberation. We need no longer be trapped in the genetically inherited behavior patterns of lizards and baboons: territoriality and aggression and dominance hierarchies. We are each of us largely responsible for what gets put in to our brains. For what as adults we wind up caring for and knowing about. No longer at the mercy of the reptile brain we can change ourselves. Think of the possibilities.

Science is a way of thinking that helps you not to fool yourself.

I think the health of our civilization, the depth of our awareness about the underpinnings of our culture, and our concern for the future, can all be tested by how well we support our libraries.

As agonizing a disease as cancer is, I do not think it can be said that our civilization is threatened by it. ... But a very plausible case can be made that our civilization is fundamentally threatened by the lack of adequate fertility control. Exponential increases of population will dominate any arithmetic increases, even those brought about by heroic technological initiatives, in the availability of food and resources, as Malthus long ago realized.