I have often had cause to feel that my hands are cleverer than my head. That is a crude way of characterizing the dialectics of experimentation. When it is going well, it is like a quiet conversation with Nature. One asks a question and gets an answer, then one asks the next question and gets the next answer. An experiment is a device to make Nature speak intelligibly. After that, one only has to listen.

As you lecture, you keep watching the faces, and information keeps coming back to you all the time.

Most modern biologists, having reviewed with satisfaction the downfall of the spontaneous generation hypothesis, yet unwilling to accept the alternative belief in special creation, are left with nothing.

I have lived much of my life among molecules. They are good company.

A scientist lives with all reality. There is nothing better. To know reality is to accept it, and eventually to love it.

I am growing old, and my future, so to speak, is already behind me.

Science goes from question to question; big questions, and little, tentative answers. The questions as they age grow ever broader, the answers are seen to be more limited.