One original thought is worth the sum total of human knowledge, because it advances the sum total of human knowledge by that one original thought.

When Da Vinci wanted an effect, he willed, he planned the means to make it happen: that was the purpose of his machines. But the machines of Newton ... are means not for doing but for observing. He saw an effect, and he looked for its cause.

The idea that the universe is running down comes from a simple observation about machines. Every machine consumes more energy than it renders.

Science is the acceptance of what works and the rejection of what does not. That needs more courage than we might think.

The progress of science is the discovery at each step of a new order which gives unity to what had seemed unlike.

We are a scientific civilization. That means a civilization in which knowledge and its integrity are crucial. Science is only a Latin word for knowledge ... Knowledge is our destiny.

Power is the by-product of understanding.