To Invent Is To Discern, To Choose.

One Geometry Cannot Be More True Than Another; It Can Only Be More Convenient.

Mathematical Discoveries, Small Or Great Are Never Born Of Spontaneous Generation.

If We Ought Not To Fear Mortal Truth, Still Less Should We Dread Scientific Truth. In The First Place It Can Not Conflict With Ethics? But If Science Is Feared, It Is Above All Because It Can Give No Happiness? Man, Then, Can Not Be Happy Through Science But Today He Can Much Less Be Happy Without It.

In The Old Days When People Invented A New Function They Had Something Useful In Mind.

When The Logician Has Resolved Each Demonstration Into A Host Of Elementary Operations, All Of Them Correct, He Will Not Yet Be In Possession Of The Whole Reality, That Indefinable Something That Constitutes The Unity ... Now Pure Logic Cannot Give Us This View Of The Whole; It Is To Intuition That We Must Look For It.