A principle is the expression of perfection, and as imperfect beings like us cannot practise perfection, we devise every moment limits of its compromise in practice.

If you read history you will find that the Christians who did most for the present world were precisely those who thought most of the next. It is since Christians have largely ceased to think of the other world that they have become so ineffective in this.

America is the spirit of human exploration distilled.

I am the center of attention in my job every single day; the thought of a wedding to me is exhausting. Why would I put myself through that?

It is possible in medicine, even when you intend to do good, to do harm instead. That is why science thrives on actively encouraging criticism rather than stifling it.