338 RAYMOND J. NOGAR 



by the value of the conclusions which are obtained by pains- 

 taking methods in this most inaccessible of scientific materials 

 — the events which took place millions of years ago, unwit- 

 nessed by any human being.^^ A patient study of the methods 

 of geology, archaeology and paleontology manifests two signifi- 

 cant points: (1) " facts " based upon evidence and inference 

 proper to scientific prehistory are sui generis, and, in them- 

 selves, highly conjectural and logically tentative; and (2) the 

 convergence of prehistoric " facts " with the evidence and in- 

 ferences drawn from neo-science (biology, anthropology, etc.) 

 yields an unexpected reasonable basis for a series of important 

 convictions about what happened during these past eons of 

 time. Scientific prehistory should neither be overstated, nor 

 underrated, in its ability to resolve some of the problems of 

 origins.^® 



Fact as a Reasonable Conviction 



Remembering the distinctions made thus far about the way 

 the term " fact," whether from evidence or inference, is used 

 variously in the sciences depending upon the availability of 

 such evidence and inference, it becomes easier to understand 

 what is meant by the statement made by Olson, and repeated 

 at the Darwin Centennial Celebration: 



Organic evolution — the process of orderly change of successive gen- 

 erations through time — does occur and apparently has occurred 

 for the total period of life on the earth. There can be many theories 

 of how it occurred, each of which may explain part or all of what 

 has been observed, and these theories may be in complete conflict 

 without invalidating the basic fact of evolution. 



30 



In the first place, Olson recognizes, as do all those who take 

 the pains to qualify their conclusions with the appropriate 



"^ Good introduction to the methods of prehistory can be found in G. G. Simpson, 

 Life of the Past (New Haven, 1953) and J. R. Beerbower, Search for the Past 

 (Englewood CHffs, N. J, 1960) . 



'^ Tendency to underrate scientific prehistory is a limitation of works such as 

 G. H. Duggan, S. M., Evolution and Philosophy (Wellington, New Zealand, 1959) . 



"" EAD, I, 527. 



