One may be unwilling to concede the hypothesis. But no one can deny that inference from one thing to another is itself an empirical event, and that just as soon as such inference occurs, even in the simplest form of anticipation and prevision, a world exists like in kind to that of the adult. I cannot think that it is a trivial coincidence that psychological analysis of sense perception came into existence along with that method of experimentally controlled observation which marks the beginning of modern science. Modern science did not begin with discovery of any new kind of inference. It began with the recognition of the need of different data if inference is to proceed safely. It was contended that starting with the ordinary--or customary--objects of perception hopelessly compromised in advance the work of inference and classification. Hence the demand for an experimental resolution of the common-sense objects in order to get data less ambiguous, more minute, and more extensive. Increasing knowledge of the structure of the nervous system fell in with increased knowledge of other objects to make possible a discrimination of specific qualities in all their diversity; it brought to light that habits, individual and social (through influence on the formation of individual habits), were large factors in determining the accepted or current system of objects. It was brought to light, in other words, that factors of chance, habit, and other non-rational factors were greater influences than intellectual inquiry in determining what men currently believed about the world. What psychological analysis contributed was, then, not primitive historic data out of which a world had somehow to be extracted, but an analysis of the world which had been previously thought of and believed in, into data making possible better inferences and beliefs about the world. Analysis of the influences customarily determining belief and inference was a powerful force in the movement to improve knowledge of the world.