A person who never made a mistake never tried anything new.
If I had 20 days to solve a problem, I would take 19 days to define it
The ideas that have lighted my way have been kindness, beauty and truth.
Considered logically this concept is not identical with the totality of sense impressions referred to; but it is an arbitrary creation of the human (or animal) mind.
If we knew what it was we were doing, it would not be called research, would it?
Even a fool is wise after an event.