We seem gradually to be groping toward an understanding of the world of subatomic particles, but we really do not know how far we have yet to go in this task.

The philosophical question before us is, when we make an observation of our track in the past, does the result of our observation become real in the same sense that the final state would be defined if an outside observer were to make the observation?

If we have an atom that is in an excited state and so is going to emit a photon, we cannot say when it will emit the photon. It has a certain amplitude to emit the photon at any time, and we can predict only a probability for emission; we cannot predict the future exactly.

In talking about the impact of ideas in one field on ideas in another field, one is always apt to make a fool of oneself.

At the heart of Christian faith is the story of Jesus' death and resurrection.

Spiritual infirmities such as tepidity are caused, not only by chills but also by fevers, that is, by excessive zeal.

I think that what happens for many Christians is, they accept their particular faith, they accept it to be true, and they stop examining it. Consequently, because it's already accepted to be true, they don't examine other people's faiths... That, I think, is not healthy for a person of any faith.

Faith embraces many truths which seem to contradict each other.