PROGRESS IN THE NINETEENTH CENTURY 495 



geography; and from this beginning we now realize that there is no 

 stopping-place till we include all other examples, complex, indirect, 

 or obscure as some of them may be; for there is a graded series of 

 connecting examples from the most artful human response down to 

 the most unconscious plant response, and from the immediate re- 

 sponses of to-day back to the earliest responses of the geological ages. 



It would be most arbitrary to draw a division in our studies, when 

 no division exists in the things studied. It is therefore a piece of good 

 fortune that geographers are coming to follow the practice of geolo- 

 gists, and thus to accept among their responsibilities the great breadth 

 of physiographic and ontographic relationships existing to-day, as 

 geologists have accepted them for the past. And it is also a good for- 

 tune that biologists are coming to accept the responsibility of study- 

 ing environment as well as response: for only in this way have the 

 earth and its inhabitants really learned to know each other. I rejoice, 

 therefore, whenever a student of earth-science completes his studies 

 by carrying them forward to their organic consequences, as seen from 

 the side of the earth; and again whenever a student of biology, of 

 language, of economics, of religion, carries his studies backward to 

 a consideration of inorganic causes, as seen from the side of life: for 

 thus and thus only we may hope that the knowledge of both causes 

 and consequences shall increase in fullness. Our present understand- 

 ing of this interdependence, not only of different branches of our own 

 science, but of the branches of our own and of other sciences, is truly 

 a great step toward the solution of the wonderful riddle of the 

 world. 



The real foundation of the broad consideration of earth-science 

 rests on the continuity of ordinary processes through the long periods 

 of recorded earth-history. Nothing has so profoundly modified the 

 appreciation of other subjects, as well as of our own, as the teaching 

 of geology concerning the conception of time and the long procession of 

 orderly events that has marched through it. Such a conquest of the 

 understanding is enough to make us proud indeed ; yet when we real- 

 ize how short a share of time has been allotted to us, how sincere 

 should be our humility! To-day we may be lords of creation, powerful 

 through cephalization: yet in face of the repeated extinction of 

 dominant races in geological history, how can we think otherwise than 

 that we are clad only in a little brief authority; how can we seri- 

 ously believe that we represent the highest stage, the acme of organic 

 development, comforting and flattering as this deductive opinion 

 may be! 



The conception of the continuity of processes, without extra-natural 

 interference, has been forced to fight its way against opposition; now 

 it has gained at least a very general verbal acceptance among us, and 

 is quietly drifting into popular belief. To realize its full meaning is an 



