Quaternions came from Hamilton after his really good work had been done, and though beautifully ingenious, have been an unmixed evil to those who have touched them in any way.

To live among friends is the primary essential of happiness.

[Referring to Fourier's mathematical theory of the conduction of heat] ... Fourier's great mathematical poem.

There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.

Overwhelmingly strong proofs of intelligent and benevolent design lie around us... the atheistic idea is so nonsensical that I cannot put it into words.

Symmetrical equations are good in their place, but ' vector ' is a useless survival, or offshoot from quaternions, and has never been of the slightest use to any creature.

To measure is to know.