FACT OF EVOLUTION TO THE PHILOSOPHY OF EVOLUTIONISM 341 



Pope Pius XII in the context, not of a biological treatise, but 

 of a theological treatise. He was not concerned about bio- 

 logical or anthropological methodology; he was not writing a 

 paper for the Darwin Centennial Celebration, He was writing 

 a theological document, using the language proper to the readers 

 to whom it was addressed, namely, the outstanding theologians 

 and philosophers of the Catholic Church. He was writing pri- 

 marily for those Catholics who were familiar with the logical 

 distinctions between those arguments which generate certitude 

 and those which conclude only to a degree of probability. The 

 reason was evident. Theologians have to evaluate carefully 

 the degree of probability of scientific propositions in order to 

 place them properly in the context of another source of truth — 

 Divine Revelation. 



Pope Pius XII was not questioning the validity of the con- 

 cepts of prehistory as synthetic models organizing much of 

 organic or even cosmic science; he was not controverting the 

 evolution of species or even the possible organic relationship of 

 the human body to other primates. He was using traditional 

 logical concepts of certitude, probability, rhetorical convictions, 

 in order to show that many evolutionary propositions do not 

 enjoy certitude but only a limited degree of probability and 

 that there are many elements of evolutionary teaching which 

 are still seriously controverted — a fact which Olson and others 

 took great pains to point out to the Convention. For these 

 reasons, therefore, the " fact of evolution " could not be placed 

 in opposition to matters of Divine Faith as a truth known to be 

 demonstrated with certitude. 



It is manifest from the context of Humani Generis what 

 Pope Pius XII wished to do, namely, to call seriously into ques- 

 tion whether the " fact of evolution " explains the existence of 

 all things and supports the monistic and pantheistic opinion 

 that the world is in continual e volution. ^^ He by no means 

 contradicts the assertions of Dobzhansky, Le Gros Clark, 

 Olson and others that the objective observer, looking without 



^^ Humani Generis, ed. dt., p. 6. 



