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

Wrong hypotheses, rightly worked from, have produced more useful results than unguided observations.

Mathematicians care no more for logic than logicians for mathematics.

[About Francis Baily] The history of the astronomy of the nineteenth century will be incomplete without a catalogue of his labours. He was one of the founders of the Astronomical Society, and his attention to its affairs was as accurate and minute as if it had been a firm of which he was the chief clerk, with expectation of being taken into partnership.

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

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

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