THEISM AND E VOLUTION. 317 



instance to be understood in its modern sense, it 

 would, as Pere Leroy puts it, be tantamount to ad- 

 mitting the " principle of materialism." 1 Obviously, 

 therefore, the term genus is to be understood in a 

 much more comprehensive sense. For a similar 

 reason, species, the immediate subdivision of genus, 

 must likewise have a much wider signification than 

 it has in a strict technical sense. If we desire to 

 have a measure of the relative amplitude of species 

 as compared with genus, in the passage just quoted, 

 in which genus is made to embrace man and animal, 

 we must, as Pere Leroy pertinently remarks, make 

 species correspond to what naturalists now denomi- 

 nate a kingdom. Thus understood, species, in the 

 instance referred to, would be immutable, but not 

 otherwise. 



It is a mistake, then, to suppose that the mean- 

 ing of the term species, in its physiological sense, 

 was fixed by the Angelic Doctor. Neither did it 

 receive the signification afterwards ascribed to it 

 from any of the other Schoolmen or mediaeval the- 

 ologians. Nor does such a meaning find any war- 

 rant in the teachings of the Fathers or in Scripture. 

 Whence, then, the origin of the word in the sense 

 so long attributed to it by special creationists ? This 

 is a question deserving of consideration, for an an- 

 swer to it, if it does not remove wholly many diffi- 

 culties, will at least clear the field for intelligent 

 discussion. 



1 For an interesting discussion of Thomastic teaching re- 

 specting the nature of species, see chap, in of Pere Leroy's 

 " L'fivolution Restreinte aux Especes Organiques." 



