66 POPULAR SCIENCE MONTHLY 



THE METHODS OF THE EARTH-SCIENCES.* 



By Professor T. C. CHAMBERLIN 



UNIVERSITY OF CHICAGO. 



IT is my assigned task to review the methods of the earth-sciences. 

 The technical processes of the constituent sciences are peculiar 

 to each and are inappropriate subjects for discussion before this com- 

 posite assemblage; but the fundamental methods of intellectual pro- 

 cedure are essentially common to all the earth-sciences, and to these 

 the address will confine itself. 



That which passes under the name earth-science is not all science 

 in the strict sense of the term. Not a little consists of generalizations 

 from incomplete data, of inferences hung on chains of uncertain logic, 

 of interpretations not beyond question, of hypotheses not fully verified 

 and of speculation none too substantial. A part of the mass is true 

 science, a part is philosophy, as I would use the term, a part is specu- 

 lation, and a part is yet unorganized material. However, I like to 

 think of the aggregate, not as an amorphous mixture of science, phi- 

 losophy and speculation, but as a rather definite aggregation of these, 

 not unlike that of the earth itself. The great mass of our subject- 

 material may be regarded as a lithosphere of solid facts. Around this 

 gathers an atmosphere of philosophy, rather dense near the contact 

 zone, but thinning away into tenuous speculation in the outer regions. 

 For myself, I like to think of the nucleus as solid and firm throughout, 

 not as a thin fractured crust floating on a fiery liquid of plutonian 

 suggestiveness. I like to think of the philosophic and speculative 

 atmosphere as no mere gas-zone of forty-five miles' depth, as of old, 

 but as an envelope of intense kinetic life, in the denser zone, where 

 the logical molecules touch one another with marvelous frequency, and 

 where there is frictional contact with the solid but rather inert litho- 

 sphere. In the outer tenuous zone, the molecular flights are freer and 

 the excursions are without assignable limits. I believe an appropriate 

 atmosphere of philosophy is as necessary to the wholesome intellectual 

 life of our sciences as is the earth's physical atmosphere to the life 

 of the planet. None the less, it must ever be our endeavor to reduce 

 speculation to philosophy, and philosophy to science. For the perpetua- 

 tion of the necessary philosophic atmosphere, we may safely trust to the 

 evolution of new problems concurrently with the solution of the old. 



But granting the importance of the philosophic element, we doubt- 



* An address at the International Congress of Arts and Science, St. Louis, 

 September, 1904. 



