Joseph LeConte Quote

We have defined geology as the history of the evolution of the earth. Evolution, therefore, is the central idea of geology. It is this idea alone which makes geology a distinct science.

Elements of Geology: A Text-book for Colleges and for the General, Reader (5th edition) (p. 421), D. Appleton & Co. 1903

We have defined geology as the history of the evolution of the earth. Evolution, therefore, is the central idea of geology. It is this idea alone...

We have defined geology as the history of the evolution of the earth. Evolution, therefore, is the central idea of geology. It is this idea alone...

We have defined geology as the history of the evolution of the earth. Evolution, therefore, is the central idea of geology. It is this idea alone...

We have defined geology as the history of the evolution of the earth. Evolution, therefore, is the central idea of geology. It is this idea alone...