Don't pay attention to "authorities," think for yourself.

What is necessary for 'the very existence of science,' and what the characteristics of nature are, are not to be determined by pompous preconditions, they are determined always by the material with which we work, by nature herself. We look, and we see what we find, and we cannot say ahead of time successfully what it is going to look like. ... It is necessary for the very existence of science that minds exist which do not allow that nature must satisfy some preconceived conditions.

I find that teaching and the students keep life going, and I would never accept any position in which somebody has invented a happy situation for me where I don't have to teach. Never.

I think it's much more interesting to live not knowing than to have answers which might be wrong.

No man is rich who is unsatisfied, but who wants nothing possess his heart's desire.

Science is uncertain.

If you have any talent, or any occupation that delights you, do it, and do it to the hilt. Don't ask why, or what difficulties you may get into.