doctrine as a whole are tenaciously retained. The result is a complete nruddle in scientific thought, in philosophic cosmology, and in epistemology. But any doctrine which does not implicitly presuppose this point of view is assailed as unintelligible.
The first item to be abandoned was the set of qualifications which we distinguish in sense-perception — namely, colour, sound, scent, and analogous qualifications. The transmission theories for light and sound introduced the doctrine of secondary qualities. The colour and the sound were no longer in Nature. They are the mental reactions of the percipient to internal bodily locomotions. Thus, Nature is left with bits of matter, qualified by mass, spatial relations, and the change of such relations.
This loss of the secondary qualities was a severe restriction to Nature, for its value to the percipient was reduced to its function as a mere agent of excitement, Also, the de-
