Chapter II 



UNIFORMITARIANISM AND ACTUALISM 



PHILOSOPHIZING ABOUT UNIFORMITARIANISM AND ACTUALISM 



The two words heading this chapter have almost the same meaning. 

 They express the assumption of a certain continuity of physical pro- 

 cesses in geological histor)-. Anglo-Saxons mainly use the word uni- 

 formitarianism, but continental Europeans, in their own languages, 

 denote the same principle with words like actualisme (French) or 

 Aktualismus (German). These words lend themselves very easily to 

 a sort of pseudo-translation into 'actualism' as the English version. 



This notwithstanding, it also happens that the two words highlight 

 two sides of one and the same line of reasoning which is basic to all 

 modem geology. Physical processes, both on the earth and in the 

 earth, are thought to be subject to unchanging natural laws and 

 therefore more or less continuous and uniform over the past; hence 

 the word uniformitarianism. Once this assumption is accepted, one 

 may study actual processes and extrapolate these into the geological 

 past to interpret our factual findings in forming a genetical, historical 

 picture. Hence the word actualism. 



Uniformitarianism, or actualism, is opposed to the earher doctrine 

 of catastrophes, as applied to geologic history. 



Before entering further into this matter of continuity versus catas- 

 trophes, it is best, I think, to introduce a digression about the value 

 of such basic philosophical principles in geology, in order to realise 

 what place such basic lines of thought as uniformitarianism have in 

 geology. 



To speak at all about philosophy in context with geology will 

 perhaps seem unfortunate to some, to use an understatement, because 

 only rarely are geologists good philosophers. This in turn stems, I 

 believe, from the fact that the phenomena our great planet offers 

 for study are so immensely varied that no mere description is ever 



