ABSTRACT
This chapter considers the development of Ptolemaic and Copernican hypotheses. The mode in which a scientific hypothesis develops, and in its development is gradually freed from anthropomorphic elements, can be most easily illustrated from the science of astronomy. The hypothesis accounts for the backward movement of the planet at some stages of its revolution. The restriction is the natural result of the increasing complexity and subtlety of scientific theories and the increased skill in the devising and manipulation of scientific apparatus. But from the logical point of view we must recognize that there is experiment wherever there is deliberate observation of expected results. A simple hypothesis framed to account for a comparatively simple fact, or set of facts, may be suggested by any one of ordinary sagacity provided that he has the requisite knowledge of relevant facts. The descriptive hypothesis may develop into an analogical hypothesis.
