Never lose a holy curiosity. Try not to become a man of success but rather try to become a man of value. He is considered successful in our day who gets more out of life than he puts in. But a man of value will give more than he receives.
Creating a new theory is not like destroying an old barn and erecting a skyscraper in its place. It is rather like climbing a mountain and gaining new and wider views.
Pure mathematics is, in its way, the poetry of logical ideas. ... [By seeking] logical beauty spiritual formulas are discovered necessary for the deeper penetration into the laws of nature.
How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?