Sociology is the science with the greatest number of methods and the least results.

Logic sometimes makes monsters. For half a century we have seen a mass of bizarre functions which appear to be forced to resemble as little as possible honest functions which serve some purpose.

It may be appropriate to quote a statement of Poincare, who said (partly in jest no doubt) that there must be something mysterious about the normal law since mathematicians think it is a law of nature whereas physicists are convinced that it is a mathematical theorem.

If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living

Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered.

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.

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.