THEISM AND E VOL UTION. 287 



regarding these subjects were as vague and diverse 

 as they are known to have been in his day. Neither 

 he nor his contemporaries had any means of throw- 

 ing light on the questions involved. Even now, 

 after all the splendid triumphs which chemistry 

 has witnessed since the epoch-making achievements 

 of Lavoisier, we are still in ignorance as to the 

 exact number of elements existing, and are yet de- 

 bating whether all the so-called elements may not 

 be so many allotropic conditions of one and the 

 same kind of matter. But what the Angelic Doctor 

 did wish to insist on, what he wished specially to 

 bring home to his hearers, was the great dogmatic 

 truth according to which God is the Creator of all 

 things, material and immaterial, visible and invisi- 

 ble. 



Materia prima, however, as understood by the 

 Scholastics, is quite different from what we know as 

 elementary matter. In all bodies subject to genera- 

 tion and corruption, it is, they tell us, numerically 

 one una numero in omnibus. l It is one and the same 

 in all the components of the earth, and in all the con- 

 stituent orbs of space. Of its very nature it is " un- 

 generated, ungenerative, indivisible, incorruptible, 

 indestructible." 2 But this" materia prima, although 

 an entity, is not a complete substance. It cannot 

 exist by itself, but must be actuated by some form. 

 For it is form which determines matter and gives 



1 " Sciendum est etiam, quod materia prima dicitur una 

 numero in omnibus." Opusc. XXXI, " De Principiis Naturae," 

 ante med. 



2 " Sciendum est quod materia prima, et etiam forma, non 

 generatur neque corrupitur." Op. cit. 



