It is a test of true theories not only to account for but to predict phenomena.

Geometry in every proposition speaks a language which experience never dares to utter; and indeed of which she but halfway comprehends the meaning.

Prudence supposes the value of the end to be assumed, and refers only to the adaptation of the means. It is the relation of right means for given ends.

Man is the interpreter of nature, science the right interpretation.

But with regard to the material world, we can at least go so far as this;-we can perceive that events are brought about, not by insulated interpositions of Divine power, exerted in each particular ease, but by the establishment of general laws.

The person who did most to give to analysis the generality and symmetry which are now its pride, was also the person who made mechanics analytical; I mean Euler.

In art, truth is a means to an end; in science, it is the only end.