Ordinarily it would take me about fifteen minutes to get a hallucination going," wrote Feynman, "but on a few occasions, when I smoked some marijuana beforehand, it came very quickly.

It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible.

We have a habit in writing articles published in scientific journals to make the work as finished as possible, to cover up all the tracks, to not worry about the blind alleys or describe how you had the wrong idea first, and so on. So there isn't any place to publish, in a dignified manner, what you actually did in order to get to do the work, although, there has been in these days, some interest in this kind of thing.

Start out understanding religion by saying everything is possibly wrong... As soon as you do that, you start sliding down an edge which is hard to recover from.

Progress in science comes when experiments contradict theory.

If the professors of English will complain to me that the students who come to the universities, after all those years of study, still cannot spell 'friend,' I say to them that something's the matter with the way you spell friend.

Work as hard and as much as you want to on the things you like to do the best.