The best result of mathematics is to be able to do without it.

Shall I refuse my dinner because I do not fully understand the process of digestion?

Waves from moving sources: Adagio. Andante. Allegro moderato.

Euclid for children is barbarous.

...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.