"When he [Newton] uttered his Hypotheses non fingo he was saying in a very abbreviated, and hence cryptic way: In induction, I do not invent hypotheses, and in deduction I do not demonstrate from them. More fully, he meant that the inductive side of scientific method has a beginning, a middle, and an end and all must be complete before any deductive system is set up. The beginning consists in '"hinting several things" or making "conjectures" about the causes of phenomena...because they are "plausible consequences" drawn from the facts...they are not derived, like Descartes' conclusions, merely by the Light of Reason or intuition. Although hypothetical in character, Newton did not call them "hypotheses". The middle consists of examining these "hints" and improving them by observations and the tests of experiment. The end is defined by his remark: "and if no exception occur from phenomena, the conclusion may be pronounced generally" and considered "proved" as a "general law of nature". "Afterwards,", the deduction proceeds by assuming the conclusions established as principles, and from them demonstrating the phenomena...The peculiar character of this method, the stress upon experience and the rejection of hypotheses of the Cartesian kind, may be briefly described in Berkeley's words: "It is one thing to arrive at general laws of nature from a contemplation of of the phenomena, and another to frame an hypothesis, and from thence deduce the phenomena (S, 229)."