As to writing another book on geometry [to replace Euclid] the middle ages would have as soon thought of composing another New Testament.

The moving power of mathematical invention is not reasoning but imagination.

During the last two centuries and a half, physical knowledge has been gradually made to rest upon a basis which it had not before. It has become mathematical. The question now is, not whether this or that hypothesis is better or worse to the pure thought, but whether it accords with observed phenomena in those consequences which can be shown necessarily to follow from it, if it be true

But the gambling reasoner is incorrigible: if he would but take to squaring the circle, what a load of misery would be saved.

I am perfectly convinced that I have both seen, and heard in a manner which should make unbelief impossible, things called spiritual which cannot be taken by a rational being to be capable of explanation by imposture, coincidence, or mistake.

I don't quite hear what you say, but I beg to differ entirely with you.

The Astronomer's Drinking Song Astronomers! What can avail Those who calumniate us; Experiment can never fail With such an apparatus.