It's a great game to look at the past, at an unscientific era, look at something there, and say have we got the same thing now, and where is it? So I would like to amuse myself with this game. First, we take witch doctors. The witch doctor says he knows how to cure. There are spirits inside which are trying to get out. ... Put a snakeskin on and take quinine from the bark of a tree. The quinine works. He doesn't know he's got the wrong theory of what happens. If I'm in the tribe and I'm sick, I go to the witch doctor. He knows more about it than anyone else. But I keep trying to tell him he doesn't know what he's doing and that someday when people investigate the thing freely and get free of all his complicated ideas they'll learn much better ways of doing it. Who are the witch doctors? Psychoanalysts and psychiatrists, of course.

Some people say, 'How can you live without knowing?' I do not know what they mean. I always live without knowing. That is easy. How you get to know is what I w…

The third aspect of my subject is that of science as a method of finding things out. This method is based on the principle that observation is the judge of whe…

If an apple was magnified to the size of the Earth, then the atoms in the apple would be approximately the size of the original apple.

People rag on western medicine a lot for its disregard of indirect causalities and holism, for its antisceptic deconstructivism, for its blindness to things li…

A symbol from the first, of mastery, experiments such as Hippocrates made and substituted for vague speculation stayed the ravages of plague.

But by far the greatest obstacle to the progress of science and to the undertaking of new tasks and provinces therein is found in this - that men despair and t…