CHAPTER XXXI 

 LEADING CHARACTERISTICS OF GILBERT'S WORK 



gilbert's era 



Gilbert was fortunate in his era, an era in which the rational views already introduced into 

 the discussion of geological problems by his predecessors were enlarged and confirmed. Indeed, 

 during Gilbert's lifetime geology was broadened by a rapid, almost world-wide extension of 

 observation into regions that had before been wildernesses; it was at the same time advanced by 

 a change from a freely speculative to an increasingly critical method of treatment, the reflection 

 of which was seen in the change from polemical dissension toward friendly discussion at geological 

 meetings ; and it was exalted by the adoption of a thoroughgoing evolutionary philosophy, which 

 recognized the uninterrupted continuity of natural processes, organic as well as inorganic, through 

 all geological time. In an era of extraordinary geological progress thus conditioned, Gilbert 

 was mentally at home, and he took an active part in leading many of its lines of progress. En- 

 dowed with a most reasonable spirit and altogether free from the restraint of artificial conventions, 

 he was predisposed to the development and the acceptance of a rational philosophy of nature; 

 he was never content to take old authority for truth, but always sought new truth for his author- 

 ity. Even if his first essay, an account of the mastodon, intelligently compiled in a provincial 

 atmosphere before Darwin's Origin of Species had taken root there, presented the traditional 

 view of the distinct creation of every organic species, he appears, immediately on emergence 

 into a larger field of experience and reflection, to have accepted evolution as a guiding principle; 

 and although he was never closely concerned with its organic aspects, its physical aspects made 

 him a confirmed uniformitarian. Unlike certain of his American seniors, he was one of those 

 who found competent explanation for the changes of the past, great and small, only in slow 

 processes like those of the present, and who never made extravagant drafts on forces, natural or 

 supernatural, for the accomplishment of geological changes, organic or inorganic. In case the 

 younger geologist of to-day should ask, in surprise, why Gilbert or anyone else should be praised 

 for never making extravagant drafts on such forces, that woidd only show how well Gilbert and 

 others of his generation, working against the surviving prejudices of earlier centuries, confirmed 

 the evolutionary philosophy which has come to be the unquestioned basis on which all geologists 

 of to-day advance so confidently. 



CHARACTERISTICS OF PUBLISHED WORK 



If Gilbert's published work is reviewed with the object of discovering its leading charac- 

 teristics, it is found to have been largely devoted to problems in physical geology and physiog- 

 raphy, to have been always guided by a candid reasonableness, to have been abundantly re- 

 freshed by ingenuity and originality, to have been frequently given a quantitative flavor, to 

 have been set forth with the most gratifying clearness and the most appealing fair-mindedness, 

 and on occasion to have exhibited an extraordinarily well-balanced suspension of judgment. 

 His work will be found, furthermore, to be based almost altogether on field observation and men- 

 tal reflection, seldom supplemented by the collection of specimens and rarely extended by work 

 in laboratories or museums; to represent with few exceptions his own personal studies, for he 

 was not often aided by assistants; the reports and essays that he published represented his 

 individual work to an unusual degree; to be — apart from the affairs of the national survey — 

 seldom concerned with scientific enterprises which led him into intimate association with other 

 men; and to be directed altogether to problems of unapplied science; for although he lived in an 

 age when the practical value of economic geology gained an unprecedented recognition from the 

 business world, he took no part whatever in that phase of earth studies. His occasional mathe- 

 matical discussions, of which the most elaborate example was his next-to-last published report, 

 are sometimes difficult to follow, not from obscurity on his part but from prevailing mathematical 



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