The electron is a theory. But the theory is so good we can almost consider them real.

We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt.

(Joan,1941) She wrote me a letter asking,"How can I read it?,Its so hard." I told her to start at the beginning and read as far as you can get until you're lost. Then start again at the beginning and keep working through until you can understand the whole book. And thats what she did

It is our responsibility as scientists, knowing the great progress which comes from a satisfactory philosophy of ignorance, the great progress which is the fruit of freedom of thought, to proclaim the value of this freedom; to teach how doubt is not to be feared but welcomed and discussed; and to demand this freedom as our duty to all coming generations.

What is not surrounded by uncertainty cannot be the truth.

Physics is to mathematics what sex is to masturbation.

Looking back at the worst times, it always seems that they were times in which there were people who believed with absolute faith and absolute dogmatism in something. And they were so serious in this matter that they insisted that the rest of the world agree with them. And then they would do things that were directly inconsistent with their own beliefs in order to maintain that what they said was true.