September 20, 1901.] 



SCIENCE, 



435 



point adopted by most scientific men, viz., 

 that the question of the existence of ultra- 

 physical entities, such as atoms and the 

 ether, is to be settled by the evidence, and 

 must not be ruled out as inadmissible on a 

 priori grounds. 



On the other hand, it is impossible to deny 

 that, if the mere entry on the search for the 

 concealed causes of physical phenomena is 

 not a trespass on ground we have no right 

 to explore, it is at all events the beginning 

 of a dangerous journey. 



The wraiths of phlogiston, caloric, lumi- 

 niferous corpuscles and a crowd of other 

 phantoms haunt the investigator, and as 

 the grim host vanishes into nothingness he 

 cannot but wonder if his own conceptions 

 of atoms and of the ether 



' shall dissolve, 

 And, like this insubstantial pageant faded, 

 Leave not a wrack behind.' 



But though science, like Bunyan's hero, 

 has sometimes had to pass through the 

 ' A^alley of Humiliation,' the spectres which 

 meet it there are not really dangerous if 

 they are boldly faced. The facts that mis- 

 takes have been made, that theories have 

 been propounded, and for a time accepted, 

 which later investigations have disproved, 

 do not necessarily discredit the method 

 adopted. In scientific theories, as in the 

 world around us, there is a survival of the 

 fittest, and Dr. James Ward's unsympa- 

 thetic account of the blunders of those whose 

 work, after all, has shed glory on the nine- 

 teenth century, might mutatis mutandis stand 

 for a description of the history of the ad- 

 vance of civilization. "The story of the 

 progress so far," he tells us, " is briefly 

 this : Divergence between theory and fact 

 one part of the way, the wreckage of aban- 

 doned fictions for the rest, with an unattain- 

 able goal of phenomenal nihilism and ultra- 

 physical mechanism beyond." ^ 



* James Ward, 'Naturalism and Agnosticism,' Vol. 

 I., p. 153. 



"The path of progress," says Professor 

 Karl Pearson, " is strewn with the wreck of 

 nations. Traces are everywhere to be seen 

 of the hecatombs of inferior races, and of 

 victims who found not the narrow way to 

 the greater perfection. Yet these dead peo- 

 ples are, in very truth, the stepping-stones 

 on which mankind has arisen to the higher 

 intellectual and deeper emotional life of 

 to-day."* 



It is only necessary to add that the prog- 

 ress of society is directed towards an un- 

 attainable goal of universal contentment, 

 to make the parallel complete. 



And so, in the one case as in the other, 

 we may leave ' the dead to bury their dead.' 

 The question before us is not whether we 

 too may not be trusting to false ideas, er- 

 roneous experiments, evanescent theories. 

 No doubt we are ; but, without making an 

 insolent claim to be better than our fathers, 

 we may fairly contend that, amid much 

 that is uncertain and temporary, some of 

 the fundamental conceptions, the root-ideas 

 of science are so grounded on reason and 

 fact that we cannot but regard them as an 

 aspect of the very truth. 



Enough has, perhaps, now been said on 

 this point for my immediate purpose. The 

 argument as to the constitution of matter 

 could be developed further in the manner I 

 have hitherto adopted, viz., by series of 

 propositions, the proof of each of which is 

 based upon a few crucial phenomena. In 

 particular, if matter is divided into moving 

 granules or particles, the phenomenon of 

 cohesion proves that there must be mutual 

 actions between them analogous to those 

 which take place between large masses of 

 matter, and which we ascribe to force, 

 thereby indicating the regular, unvarying 

 operation of active machinery which we 

 have not yet the means of adequately under- 

 standing. For the moment, I do not wish 



* Karl Pearson, ' National Life from the Standpoint 

 of Science,' p. 62. 



