TEE PROGRESS OF SCIENCE. 519 



seem like a rehearsal of tniisins. But it is one of the paradoxes of 

 human development that errors which have been completely dislodged 

 from the minds of the few may still linger persistently in the minds 

 of the many, and that the misleading hjrpotheses and the dead theories 

 of one age may be resuscitated again and again in succeeding ages. 

 Thus, to cite one of the simplest examples, it doubtless appeared clear to 

 the Alexandrian school of scientists that the flat, four-cornered earth of 

 contemporary myths would speedily give way to the revelations of geom- 

 etry and astronomy. How inadequate such revelations proved to be at 

 that time is one of the most startling disclosures in all history. The 

 'Divine School of Alexandria' passed into oblivion. The myth of a 

 flat and four-cornered earth was crystallized into a dogma strong 

 enough to bear the burden of men's souls by Cosmas Indicopleustes in 

 the sixth century; it was supported with still more invincible argu- 

 ments by Martin Luther in the sixteenth century; and it was revived 

 and maintained with not less truly admirable logic, as such, by John 

 Hampden and John Jasper in the last decades of the nineteenth cen- 

 tury. To cite examples from contemporary history showing how dif- 

 ficult it is for the human mind to get above its primitive conceptions, 

 one needs only to refer to the daily press. During the past two months, 

 in fact, the newspapers have related how multitudes of men, women 

 and children, many of them suffering from loathsome if not contagious 

 diseases, have visited a veritable middle age shrine in the city of New 

 York, strong in the hoary superstition that kissing an alleged relic of 

 St. Anne would remove their afflictions. During the same interval a 

 railway circular has been distributed explaining how tourists may wit- 

 ness the Moki snake-dance, that weird ceremony by which the Pueblo 

 Indian seeks to secure rain in his desert; and a similar public, and 

 officially approved, ceremony has been observed in the heat-stricken 

 State of Missouri. 



Such epochs and episodes of regression as these must be taken into 

 account in making up an estimate of scientific progress. They show 

 us that the slow movement upward in the evolution of man which gives 

 an algebraic sum of a few steps forward per century is not inconsistent 

 with many steps backward. Or, to state the case in another way, the 

 rate of scientific advance is to be measured not so much by the positions 

 gained and held by individuals, as by the positions attained and real- 

 ized by the masses, of our race. The average position of civilized man 

 now is probably below the mean of the positions attained by the natu- 

 ralist Huxley and the statesman Gladstone, or below the mean of the 

 positions attained by the physicist von Helmholtz and His Holiness the 

 Pope. When measured in this manner, the rate of progress in the 

 past twenty centuries is not altogether flattering or encouraging to us, 



