Originality is independence, not rebellion; it is sincerity, not antagonism.
Mathematicians do not write for the circulating library.
Heart and Brain are the two lords of life. In the metaphors of ordinary speech and in the stricter language of science, we use these terms to indicate two central powers, from which all motives radiate, to which all influences converge.
Science is the systematic classification of experience.
Sincerity is moral truth.
To one man a stream is so much water-power, to another a rendezvous for lovers.