Guessing before proving! Need I remind you that it is so that all important discoveries have been made?

It is not order only, but unexpected order, that has value.

All great progress takes place when two sciences come together, and when their resemblance proclaims itself, despite the apparent disparity of their substance.

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.

It is far better to foresee even without certainty than not to foresee at all.

But for harmony beautiful to contemplate, science would not be worth following.

In one word, to draw the rule from experience, one must generalize; this is a necessity that imposes itself on the most circumspect observer.