For even the most sober scientific investigator in science, the most thoroughgoing Positivist, cannot dispense with fiction; he must at least make use of categories, and they are already fictions, analogical fictions, or labels, which give us the same pleasure as children receive when they are told the "name" of a thing.

The Dance of Life, Chapter III, Section II (p. 94), Houghton Mifflin Company. 1923