478 THE POPULAR SCIENCE MONTHLY 



the realms of hypothesis. For generations the universities taught both 

 the geocentric and the heliocentric systems, leaving the student to de- 

 cide which was right. During more than a thousand years previous to 

 Galileo's discoveries, superstition and unreason had prevented all hu- 

 man 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 me- 

 chanical 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 tran- 

 scendental 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 at- 

 tainment 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. 



