Theory is the essence of facts. Without theory scientific knowledge would be only worthy of the madhouse.

If it is love that makes the world go round, it is self-induction that makes electromagnetic waves go round the world.

...there is no absolute scale of size in nature, and the small may be as important, or more so than the great.

Mathematics is of two kinds, Rigorous and Physical. The former is Narrow: the latter Bold and Broad. To have to stop to formulate rigorous demonstrations would put a stop to most physico-mathematical inquiries. Am I to refuse to eat because I do not fully understand the mechanism of digestion?

Facts are of not much use, considered as facts. They bewilder by their number and their apparent incoherency. Let them be digested into theory, however, and brought into mutual harmony, and it is another matter.

Theory is the essence of facts. Without theory scientific knowledge would be only worthy of the madhouse.

However absurd it may seem, I do in all seriousness hereby declare that I am animated mainly by philanthropic motives. I desire to do good to my fellow creatures, even to the Cui bonos.