104 W. M. DAVIS RELATION OF GEOGRAPHY TO GEOLOGY 



its implications have to be translated and expanded from conditions of 

 rock structure and past processes into concepts of surface form, and this 

 requires training. Being concerned only with land forms, the description 

 is lacking in climatic elements and ontographic relations, and it is there- 

 fore incompletely geographical in the sense that the treatment of a section 

 of a subject incompletely represents the whole subject; but it belongs 

 none the less under geography, because it is explanatory, advanced, con- 

 densed, and incomplete. Hence I propose still to regard this explanatory, 

 condensed description as a geographical description. 



Part II. The Necessity of explanatory Treatment in modern 



Geography 



empirical and explanatory geographical descriptions 



In spite of all that has been said thus far, some of my more conserva- 

 tive hearers may regard all the explanatory descriptions thus far cited as 

 belonging under geolog}^, because, being explanatory, such descriptions 

 necessarily have to do with the past, and in the mind of these hearers 

 nothing that has to do with the past deserves to be classed under geog- 

 raphy. There is, I fear, some reason for thinking that most of those who 

 thus object to the explanatory method of geographical description and 

 who reject such a description as that given above for the Front Eange 

 from geography were educated in the older-fashioned empirical school, 

 and have never given much attention to the newer-fashioned and more 

 rational method of geographical presentation. To them geography is only 

 an empirical subject — that is, it deals only with immediately observable 

 facts, independent of all theoretical explanations. Naturally, then, if 

 they meet a geographical problem, treated in an explanatory manner, par- 

 ticularly if it includes an account of a group of land forms treated in 

 terms of rock structure, erosional process, and stage of erosion reached, 

 they do not recognize it as geographical and think it belongs to some 

 other subject ; but it is geographical all the same, because its object is the 

 description of the visible landscape. 



Empirical geographers may, liowever, object to this assertion, and ask 

 why geography should be treated in an explanatory instead of in an 

 empirical manner; why it should thus be made to trespass so far on 

 geology as to include considerations of underground structures and past 

 processes, instead of being content to describe visible forms directly in the. 

 good old-fashioned, superficial, empirical method, without making so 

 much ado about it. A reason often given for the introduction of the 

 modern and more penetrating rational method is that explanatorv descrip- 



