errors" he tells us, "which are not born from experience, the mother of all certainty, and which do not end with one clear experiment. Science gives certainty and science gives power. Those who rely on practice without science are like sailors without rudder or compass." Had the results of his work and thought been published, instead of being preserved only in note books, science might have gained a full century. The freedom and humanism of his day, however, soon passed away and science was later compelled to make a fresh start in the face of repression and persecution.
As it was, the 17th century was to prove the crucial one in the development of the new interest, for by virtue of a handful of men of unparalleled genius, who followed one after another, that century was to see the greatest single intellectual achievement the race has yet won. Galileo prepared the way for the miracle, but it was Newton who formulated finally the laws of motion, the law of gravitation and the basic physical ideas which have served so well ever since as the foundation of astronomy and mechanical science. This achievement was the final step needed for establishing in the minds of men the idea of universal law, of the uniformity of nature, and placed science on a foundation where it has been able to follow its open path independently of national boundaries and of social and political changes. Hence the publication of Newton's Principia in 1687 "made that date pivotal in the history of science and a turning point in the history of mankind."
The Newtonian principles and methods proved astonishingly successful in dealing with the problems of chief interest in that epoch; and the 18th century devoted itself with unbounded confidence to the analysis of the universe. Science now separated itself from philosophy and has since maintained its course untrammeled by extraneous motives. Thinkers became convinced that the scientific method could be equally well brought to bear in all realms whatsoever, and rendered tremendous service in establishing in the minds of men a new confidence in the stability of the world and in the human reason. The Age of Reason which they so optimistically anticipated has not yet arrived; but science has continued its advance without interruption and pours out its products in ever increasing volume. We cannot now conceive of any retrogression that could possibly bring back the pre-scientific attitude.
THE GROWTH OF SCIENCE
Encouraged by the successes of the 17th and 18th centuries, students turned their attention to the inductive study of the phenomena of the earth's surface, and found more and more in these phenomena the same harmony and the same reign of law that they had first found in the heavens. Never was enterprise more justified of her children. Each discovery opened the way for many others and scientific knowledge and its applications increased in geometric ratio.
