Many times when I stop working on a problem consciously, my mind continues to work on it below the surface. Often solutions come on me quite by surprise. I've learned over time to allow that to happen, rather than to feel that I can simply solve the problem by continuous, grueling effort.

If we focused on using the opportunities we have, which are very great by any standard - health, longevity, comfort and privacy, endless resources of culture and information - we would not just navigate this world, we would leave a good inheritance to succeeding generations.

The loss of seriousness seems to me to be, in effect, a loss of hope. I think that the thing that made people rise to real ambition, real gravity was the sense of posterity, for example - a word that I can remember hearing quite often when I was a child and I never hear anymore. People actually wanted to make the world good for people in generations that they would never see. It makes people think in very large terms to try to liberate women, for example, or to try to eliminate slavery.

The moon looks wonderful in this warm evening light, just as a candle flame looks beautiful in the light of morning. Light within light...It seems to me to be a metaphor for the human soul, the singular light within that great general light of existence.

Christianity is a life, not a doctrine . . . I'm not saying never doubt or question. The Lord gave you a mind so that you would make honest use of it. I'm saying you must be sure that the doubts and questions are your own.

It saddens me that Christians need to be reminded that awe is owed also to those who disagree with them, who believe otherwise than they do.

A letter makes ordinary things seem important.