Nature hides her secrets because of her essential loftiness, but not by means of ruse.

However we select from nature a complex [of phenomena] using the criterion of simplicity, in no case will its theoretical treatment turn out to be forever appropriate (sufficient).... I do not doubt that the day will come when [general relativity], too, will have to yield to another one, for reasons which at present we do not yet surmise. I believe that this process of deepening theory has no limits.

Albert is a very poor student. He is mentally slow, unsociable and is always daydreaming. He is spoiling it for the rest of the class. It would be in the best interests of all if he were removed from school immediately.

If you want to find out anything from the theoretical physicists about the methods they use, I advise you to stick closely to one principle: don't listen to their words, fix your attention on their deeds. To him who is a discoverer in this field the products of his imagination appear so necessary and natural that he regards them, and would like to have them regarded by others, not as creations of thought but as given realities.

If someone feels that he has never made a mistake in his life, it only means that he has never tried anything new in his life.

Don't listen to their words, fix your attention on their deeds.

Agreements about what is good or not, are usually not worth much. It is very much like art, is it not an art to lead a good life?