8 UNIFORMITARIANISM AND ACTUALISM 



sufficient to convey a complete idea of any of its phases. No mere 

 word picture conveys all the information on even a single exposure 

 of rocks to the man who has not himself seen that spot. This is 

 borne out clearly in every travelogue of a geologist who, visiting for 

 the first time regions about which he may have heard or read ex- 

 tensiv^ely, finds that his mental picture was still very nebulous. Take 

 a European geologist to the Appalachians or the Rocky Mountains, 

 or an American to the Alps, the result will be the same. You will 

 hear your man enthuse about his luck to be able to see these areas 

 at last for himself, and so to check by personal inspection his own 

 incomplete and unbalanced impressions from the literature. 



In geological descriptions one normally finds only part of the story. 

 Either some main point is stressed, which results in oversimplifica- 

 tion, or, more often, exceptional details are diligently pointed out, 

 whilst the author forgets that only a minor part of his audience can 

 really take the general description for granted. 



If then it is wellnigh impossible to express oneself in words only, 

 this does not, of course, lead naturally to an aptitude for strong 

 philosophical essays in which ultimate meanings are conveyed by 

 words and by words only. Geologists have the tendency to supply as 

 many illustrations as feasible: photos, maps and sections. The rest 

 one has just to imagine for oneself — a trend cry^stallized, for in- 

 stance, in the slogan of a Swiss geologist: "Hingehen und gucken", 

 or "Go there and look". 



This digression was included because I think it is necessar)^ to 

 clarify this side of the geological aspect before we proceed with a 

 discussion of uniformitarianism and its bearing on the origin of life 

 on earth. Both uniformitarianism and the earlier doctrine of catas- 

 trophism belong to basic geological philosophy. They have been 

 defined and re-defined, they have had their adherents and opposers, 

 but the literature in which either of these basic lines of thought has 

 been expressly treated is scarce. The only, and veiy thorough, study 

 of uniformitarianism as such is to be found in Professor Hooykaas' 

 book. Natural Law and Divine Miracle (Hooykaas, 1960), which was 

 not written by a geologist. 



It is, as we shall see, very difficult to give a precise definition of 

 uniformitarianism or actualism. One has to content oneself with a 

 very general outline which leaves room for borderline cases. To most 



