132 MR. DARWIN’S CRITICS Vv 
particles and forces, in virtue of which last these 
particles assume those dispositions and exercise 
those powers which are characteristic of each 
particular kind of matter. 
But the Schoolmen distinguished two kinds of 
substantial forms, the one spiritual and the other 
material. The former division is represented by 
the human soul, the anima rationalis; and they 
affirm as a matter, not merely of reason, but of 
faith, that every human soul is created out of 
nothing, and by this act of creation is endowed 
with the power of existing for all eternity, apart — 
from the materia prima of which the corporeal 
frame of man is composed. And the anima 
vationalis, once united with the materia prima of 
the body, becomes its substantial form, and is the 
source of all the powers and faculties of man—of 
all the vital and sensitive phenomena which he ~ 
exhibits—just as the substantial form of water is 
the source of all its qualities. | 
The “material substantial forms” are those 
which inform all other natural bodies except that 
of man; and the object of Suarez in the present 
Disputation, is to show that the axiom “ex nihilo 
nial fit,’ though not true of the substantial form — 
of man, is true of the substantial forms of all 
other bodies, the endless mutations of which 
constitute the ordinary course of nature. The 
origin of the difficulty which he discusses is easily 
comprehensible. Suppose a piece of bright iron 
