I hope that some day the practice of producing cowpox in human beings will spread over the world - when that day comes, there will be no more smallpox.

Society has always to demand a little more from human beings than it will get in practice.

Human beings are a wonderful virus in some ways.

If we were logical, the future would be bleak, indeed. But we are more than logical. We are human beings, and we have faith, and we have hope, and we can work.

When it comes to the pinch, human beings are heroic.

Human beings have always been mythmakers.