He used to say to his melancholia patients: "You can be cured in fourteen days if you follow this prescription.Try to think every day how you can please someone.

We must never neglect the patient's own use of his symptoms.

If you wish to educate a child who has gone wrong, then you must, above all, keep your attention fixed on the intersection of two charmed circles.

Mathematics is pure language - the language of science. It is unique among languages in its ability to provide precise expression for every thought or concept that can be formulated in its terms.

The chief danger in life is that you may take too many precautions.

God who is eternally complete, who directs the stars, who is the master of fates, who elevates man from his lowliness to Himself, who speaks from the cosmos to every single human soul, is the most brilliant manifestation of the goal of perfection.

Each generation has its few great mathematicians, and mathematics would not even notice the absence of the others. They are useful as teachers, and their research harms no one, but it is of no importance at all. A mathematician is great or he is nothing.