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

Teach principles not formulas.

Why make yourself miserable saying things like, "Why do we have such bad luck? What has God done to us? What have we done to deserve this?" - all of which, if you understand reality and take it completely into your heart, are irrelevant and unsolvable. They are just things that nobody can know. Your situation is just an accident of life.

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.

Our poets do not write about it; our artists do not try to portray this remarkable thing. I don't know why. Is nobody inspired by our present picture of the universe? The value of science remains unsung by singers... This is not yet a scientific age.

Words can be meaningless. If they are used in such a way that no sharp conclusions can be drawn.

All we know so far is what doesn't work.