Fudging the data in any way whatsoever is quite literally a sin against the holy ghost of science. I'm not religious, but I put it that way because I feel so strongly. It's the one thing you do not ever do. You've got to have standards.

'Science in itself' is nothing, for it exists only in the human beings who are its bearers. 'Science for its own sake' usually means nothing more than science for the sake of the people who happen to be pursuing it.

There are always more questions. Science as a process is never complete. It is not a foot race, with a finish line.... People will always be waiting at a particular finish line: journalists with their cameras, impatient crowds eager to call the race, astounded to see the scientists approach, pass the mark, and keep running. It's a common misunderstanding, he said. They conclude there was no race. As long as we won't commit to knowing everything, the presumption is we know nothing.

The conquest of space is not merely a technological project of interest to a handful of select scientists and specialists, valuable though that research and information may be.

I'm not trying to copy Nature, I'm trying to find the principles she's using.

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.