The full impact of the Lobachevskian method of challenging axioms has probably yet to be felt. It is no exaggeration to call Lobachevsky the Copernicus of Geometry [as did Clifford], for geometry is only a part of the vaster domain which he renovated; it might even be just to designate him as a Copernicus of all thought.

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

Euclid taught me that without assumptions there is no proof. Therefore, in any argument, examine the assumptions.

If "Number rules the universe" as Pythagoras asserted, Number is merely our delegate to the throne, for we rule Number.

I have always hated machinery, and the only machine I ever understood was a wheelbarrow, and that but imperfectly.

Time makes fools of us all. Our only comfort is that greater shall come after us.

Nevertheless, the consuming hunger of the uncritical mind for what it imagines to be certainty or finality impels it to feast upon shadows in the prevailing famine of substance.