Obvious is the most dangerous word in mathematics.

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

The very basis of creative work is irreverence! The very basis of creative work is bold experimentation. There has never been a creator of lasting importance who has not also been an innovator.

If indeed, as Hilbert asserted, mathematics is a meaningless game played with meaningless marks on paper, the only mathematical experience to which we can refer is the making of marks on paper.

Obvious is the most dangerous word in mathematics.

Poincaré was a vigorous opponent of the theory that all mathematics can be rewritten in terms of the most elementary notions of classical logic; something more than logic, he believed, makes mathematics what it is.

Science makes no pretension to eternal truth or absolute truth.