As one sharpens a knife on a whetstone, the brain can be sharpened on dull objects of thought. Every form of assiduous thinking has its value.

I'm an agnostic. Sometimes I muse deeply on the forces that are for me invisible. When I am almost close to the idea of God, I feel immediately estranged by the horrors of this world, which he seems to tolerate...
Stanislaw UlamIt is most important in creative science not to give up. If you are an optimist you will be willing to "try" more than if you are a pessimist.
Stanislaw UlamThanks to my memory, which enabled me to quote Latin and to discuss Greek and Roman civilization, it became obvious to some of my colleagues in other fields that I was interested in things outside mathematics. This lead quickly to very pleasant relationships.
Stanislaw UlamBy an incredible coincidence, Gamow and Edward Condon, who had discovered simultaneously and independently the explanation of radioactivity (one in Russia, the other in this country), came to spend the the last ten years of their lives within a hundred yards of each other in Boulder.
Stanislaw UlamThe mathematicians know a great deal about very little and the physicists very little about a great deal.
Stanislaw UlamWhatever is worth saying, can be stated in fifty words or less.
Stanislaw UlamThe first sign of senility is that a man forgets his theorems, the second sign is that he forgets to zip up, the third sign is that he forgets to zip down.
Stanislaw UlamDo not lose your faith. A mighty fortress is our mathematics. Mathematics will rise to the challenge, as it always has.
Stanislaw UlamSometimes I feel that a more rational explanation for all that has happened during my lifetime is that I am still only thirteen years old, reading Jules Verne or H. G. Wells, and have fallen asleep.
Stanislaw UlamI thought that the description of Don Quixote's fight with the windmills the funniest thing imaginable.
Stanislaw UlamFor many years I was the youngest among my mathematical friends. It makes me melancholy to realize that I now have become the oldest in most groups of scientists.
Stanislaw UlamAda came from Lwów. She was a very good looking girl who was studying mathematics at the University of Geneva. For a few years I had an offandon romance with her.
Stanislaw UlamIt was not so much that I was doing mathematics, but rather that mathematics had taken possession of me.
Stanislaw UlamAs a mathematician, von Neumann was quick, brilliant, efficient, and enormously broad in scientific interests beyond mathematics itself. He knew his technical abilities; his virtuosity in following complicated reasoning and his insights were supreme; yet he lacked absolute self confidence.
Stanislaw UlamWith sixty professors there are roughly eighteen hundred pairs of professors. Out of that many pairs it was not surprising that there were some whose members did not like one another.
Stanislaw UlamIn mathematics, as in physics, so much depends on chance, on a propitious moment.
Stanislaw UlamI am always amazed how much a certain facility with a special and apparently narrow technique can accomplish.
Stanislaw UlamThere may be such a thing as habitual luck. People who are said to be lucky at cards probably have certain hidden talents for those games in which skill plays a role. It is like hidden parameters in physics, this ability that does not surface and that I like to call "habitual luck".
Stanislaw UlamIn many cases, mathematics is an escape from reality. The mathematician finds his own monastic niche and happiness in pursuits that are disconnected from external affairs. Some practice it as if using a drug.
Stanislaw UlamVery soon I discovered that if one gets a feeling for no more than a dozen other radiation and nuclear constants, one can imagine the subatomic world almost tangibly, and manipulate the picture dimensionally and qualitatively, before calculating more precise relationships.
Stanislaw UlamAccording to recent studies, at least one star out of three is multiple.
Stanislaw UlamWhat exactly is mathematics? Many have tried but nobody has really succeeded in defining mathematics; it is always something else.
Stanislaw UlamIn its evolution from a more primitive nervous system, the brain, as an organ with ten or more billion neurons and many more connections between them must have changed and grown as a result of many accidents.
Stanislaw UlamThoughts are steered in different ways.
Stanislaw UlamI am turned off when I see only formulas and symbols, and little text.
Stanislaw UlamMathematics may be a way of developing physically, that is anatomically, new connections in the brain.
Stanislaw Ulam