the realms of hypothesis. For generations the universities taught both the geocentric and the heliocentric systems, leaving the student to decide which was right. During more than a thousand years previous to Galileo's discoveries, superstition and unreason had prevented all human progress. They were the source of untold mischief and suffering and are still man's greatest enemy, while science and reason are his greatest friends. Modern superstitions are often the best comment on ancient astronomical errors.
Newton's astrophysical discoveries placed the solar system on a mechanical basis and dispensed with the planetary guiding angels. Empirical science has since shown that every phenomenon has its mechanical cause, while Darwin's "Descent of Man" has shattered the dogma of anthropocentricism. In the operation of cosmic forces it may now be said that events occur by mechanical necessity regardless of man's interests. During the latter half of the nineteenth century, by the telescopic study of the vast and the microscopic study of the small, a splendid record of accumulated truths was attained. The discoveries of the laws of the indestructibility of force and matter, the unity of nature, the mechanical theory of heat; inorganic and organic evolution and the universality of law, have explained many mysterious phenomena, and forced them out of the darkness of the supernatural to the light of the natural. It has been said that mystery has now been driven from the universe. Belief in the miraculous and the transcendental rests on the assumption that outside and beyond the natural world active forces exist that have no material basis, and of which we can learn nothing by experience, or by any natural means. Such dualistic beliefs are purely idealistic and are evolved from the activity of the brain called emotion. Emotion has nothing to do with the attainment of truth and all doctrines, or opinions, are to be suspected, that are favored by our passions.
Philosophy is the science of which all others are but branches, hence philosophy lies in the province of physical science and not in that of letters. Haeckel says: "All true natural science is philosophy and all true philosophy is natural science." The astronomical errors of the past have arisen from attempts to explain the cosmos out of the inner consciousness, rejecting all scientific methods and substituting faith. While faith may supplement observation in the search for truth, we must not confuse supernatural faith with the natural faith of science. Mark Twain has defined the former as "believing something that you know is not true." The natural faith of science and of practical life is drawn from experience. Kant, Hume, Huxley and Haeckel agree that all knowledge of the reality of phenomena is limited to that revealed to us by experience. Belief must rest on evidence. That belief which is not founded on evidence is both illogical and immoral.
