Obvious is the most dangerous word in mathematics.

Even stranger things have happened; and perhaps the strangest of all is the marvel that mathematics should be possible to a race akin to the apes.

The longer mathematics lives the more abstract - and therefore, possibly also the more practical - it becomes.

Any impatient student of mathematics or science or engineering who is irked by having algebraic symbolism thrust upon him should try to get along without it for a week.

The only royal road to elementary geometry is ingenuity.

The pursuit of pretty formulas and neat theorems can no doubt quickly degenerate into a silly vice, but so can the quest for austere generalities which are so very general indeed that they are incapable of application to any particular.

Science makes no pretension to eternal truth or absolute truth.