468 Catastrophism and Evolution. [ August, 
From their conclusions and philosophy let us turn, but with 
no revolt of prejudice, no rebound of a happier intuition, for this 
is a question of science. Those who defend the stronghold of 
natural selection are impregnable to the assaults of feeling. 
They are dislodged only by the solid projectiles of fact, and to 
facts cast in the mold of nature they count it no dishonor to 
surrender. If, as I have said, the evolution and power of envi- 
ronment have been singularly neglected studies, if biologists 
have allowed the splendor of their achievements within the prov- 
ince of life to blind them to the working of that other and no 
less important side of the problem, what then is the general re- 
lation in time and space of the inorganic environment to life? 
Let us first acknowledge frankly that the present and later 
parts of the Quaternary period are uniformitarian ; that the 
changes going on in organic life now do obey the great law of 
survival of the fittest, and that if the uniformitarians were true 
in making of the past a mere infinite projection of the present, 
then the biologists would have based their theories on a solid 
foundation, and my protest would have no weight. Let us go 
further and cordially admit that in all periods of uniformity the 
progress of life would adjust itself to its surroundings, and the 
war of competitive extermination become the dominant engine of 
change and development. This is giving full credit to the great- 
ness of the biological result, and simply asserts that they who 
achieved it are sound as far as the analogy of present uniformity 
may be permitted to go. But uniformity has not been the sole 
law; it has, as we have seen, been often broken by catastrophes, 
—that is, by accelerated rate of change. Rapid physical change 
has been, it seems to me, the more important of the two condi- 
tions of the past, the one whose influence will at last prove to 
have been the dominant one in life change. 
Has environment, with all the catastrophic changes, been 
merely passive as regards life? It has either had no effect, oF 
has restrained the progress of evolution, or has advanced it, or its 
influence has been as varied as its own history, — now by the de- 
velopment of favoring conditions accelerating vital progress, NOW 
suddenly exterminating on a vast scale, again urging evolution 
forward, again leaving lapses of calm in which species took | 
matter into their own hands and worked out their own destiny: 
— It is only through rapid movements of the crusts and sudden cli- 
matic changes, due either to terrestrial or cosmical causes, that 
environment can have seriously interfered with the evolution of 
