Science is a human activity, and the best way to understand it is to understand the individual human beings who practise it. Science is an art form and not a philosophical method. The great advances in science usually result from new tools rather than from new doctrines. ... Every time we introduce a new tool, it always leads to new and unexpected discoveries, because Nature's imagination is richer than ours.

Humanity looks to me like a magnificent beginning but not the final word.

It is not surprising that honest and well-informed experts can disagree about facts. But beyond the disagreement about facts, there is another deeper disagreement about values.

Our thinking is permeated by our historical myths

Climate change is part of the normal order of things, and we know it was happening before humans came.

Aviation is the branch of engineering that is least forgiving of mistakes.

One factor that has remained constant through all the twists and turns of the history of physical science is the decisive importance of the mathematical imagination.