Mathematical discoveries, small or great are never born of spontaneous generation They always presuppose a soil seeded with preliminary knowledge and well prepared by labour, both conscious and subconscious.

Intuition is more important to discovery than logic.

When the physicists ask us for the solution of a problem, it is not drudgery that they impose on us, on the contrary, it is us who owe them thanks.

Ideas rose in clouds; I felt them collide until pairs interlocked, so to speak, making a stable combination.

In the old days when people invented a new function they had something useful in mind.

Pure logic could never lead us to anything but tautologies; it can create nothing new; not from it alone can any science issue.

Thought is only a flash between two long nights, but this flash is everything.