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

Electric and magnetic forces. May they live for ever, and never be forgot, if only to remind us that the science of electromagnetics, in spite of the abstract nature of its theory, involving quantities whose nature is entirely unknown at the present, is really and truly founded on the observations of real Newtonian forces, electric and magnetic respectively.

Mathematics is an experimental science, and definitions do not come first, but later on.

Logic can be patient, for it is eternal.

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?

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

Why should I refuse a good dinner simply because I don't understand the digestive processes involved?