Nothing can be more fatal to progress than a too confident reliance on mathematical symbols; for the student is only too apt to take the easier course, and consider the formula not the fact as the physical reality.

Mathematics is the only good metaphysics.

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

Christianity without the cross is nothing. The cross was the fitting close of a life of rejection, scorn and defeat. But in no true sense have these things ceased or changed. Jesus is still He whom man despiseth, and the rejected of men. The world has never admired Jesus, for moral courage is yet needed in every one of its high places by him who would "confess" Christ. The "offense" of the cross, therefore, has led men in all ages to endeavor to be rid of it, and to deny that it is the power of God in the world.

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.

The vortex theory [of the atom] is only a dream. Itself unproven, it can prove nothing, and any speculations founded upon it are mere dreams about dreams.

The only census of the senses, so far as I am aware, that ever before made them more than five, was the Irishman's reckoning of seven senses. I presume the Irishman's seventh sense was common sense; and I believe that the possession of that virtue by my countrymen-I speak as an Irishman.