208 W. A. WALLACE 



merit is based on the very passivity of gravitating bodies. By 

 the terms of the objection, every passion must be accompanied 

 by a simultaneous action, and thus, if the generator is the 

 moving agent, it must actually accompany falling bodies " with 

 a continual influx of motion," and this " we do not see." *' 

 A fifth argument he draws from mathematics. A generator 

 causes a triangle, and thus according to the explanation under 

 discussion, causes all the natural accidents which flow from its 

 quiddity, including that its angles equal two right angles; but 

 it is " absurd " to say that the triangle in itself does not have 

 this property, and gets it continually from the generator.*^ 



The sixth argument depends on the supposition that fire, or 

 any other element, might be eternal, and on this supposition 

 would not have a generator. Theodoric maintains that nat- 

 urally " it still would be moved up," without the action of the 

 non-existent generator.*^ His seventh argument, finally, he 

 draws from the nature of motion itself, which is an imperfect 

 act and as such requires an " actual mover producing the influx 

 of motion." Therefore, if the generator is the mover, " it must 

 actually coexist with and touch the object in motion, which is 

 contrary to what is apparent to the senses," *^ 



Having thus disposed of a prevalent interpretation of Aris- 

 totle, Theodoric turns to his own explanation of what the 

 Stagyrite means when he says that falling bodies " are moved 

 by the generator as by their principal and essential mover, 

 and by whatever removes an impediment as by their accidental 

 mover." The interpretation he proposes is based on distinctions 

 between substantial and accidental being already developed in 

 opuscula other than those now under examination. This doc- 

 trine is exposed elsewhere; ^^ here I merely report the distinc- 

 tions among accidents that are enumerated in De elementis 

 as relevant to the problem of gravitation. 



*^ Cap. 32, M 17rb, T 184v, U 145ra-b. 



"Cap. 33, M 17rb, T 184v, U 145rb. 



^' Cap. 34, M 17rb-va, T 184v, U 145rb. 



" Cap. 35, M 17va, T 184v, U 145rb. 



^''See my Scientific Methodology, pp. 26-32, 80-91, 152-161. 



