Why is it that showers and even storms seem to come by chance, so that many people think it quite natural to pray for rain or fine weather, though th… - Henri Poincaré

What we call objective reality is, in the last analysis, what is common to many thinking beings, and could be common to all; this common part, we shall see, can only be the harmony expressed by mathematical laws. It is this harmony... which is the sole objective reality, the only truth we can attain; and when I add that the universal harmony of the world is the source of all beauty, it will be understood what price we should attach to the slow and difficult progress which little by little enables us to know it better.

It is by logic that we prove, but by intuition that we discover. To know how to criticize is good, to know how to create is better.

When navigators... determine a ... they must... calculate Paris time...[with] a chronometer set for Paris. The qualitative problem of simultaneity is made to depend upon the quantitative problem of the measurement of time.