Many a man’s reputation would not know his character if they met onthe street. (Elbert Hubbard)

Each problem that I solved became a rule which served afterwards to solve other problems. (Rene Descartes, Discours de la Methode)

Problems worthy of attack prove their worth by fighting back. (Paul Erdos)

I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. (Umberto Eco)