Be not afraid of life. Believe that life is worth living, and your belief will help create the fact.

The history of philosophy is to a great extent that of a certain clash of human temperaments.

To study the abnormal is the best way of understanding the normal.

Whenever you're in conflict with someone, there is one factor that can make the difference between damaging your relationship and deepening it. That factor is attitude.

Being nimble and ready to change our minds if need be is an attribute that is crucial to live and thrive in a society that is powered by science and technology, both as an individual and as an engaged citizen.

Teaching needs an ecosystem that supports evidence-based practice. It will need better systems to disseminate the results of research more widely, but also a better understanding of research, so that teachers can be critical consumers of evidence.

Why, for example, should a group of simple, stable compounds of carbon, hydrogen, oxygen and nitrogen struggle for billions of years to organise themselves into a professor of chemistry? What's the motive?

We are all enormously indebted to the National Science Foundation of the United States and the American public for steady support over close to 50 years.