GRAVITATIONAL MOTION 213 



sustains every natural substance in being. It is also, for 

 Theodoric, what gives it actuality during its transitional stage, 

 or sustains its motion: 



The influx of this cause is found not only when the thing has been 

 constituted in being, but also in a certain way in its changing, for 

 otherwise the influx would already have ceased, and if this were 

 the only action of the universally first cause, then the being of the 

 thing would not be restricted to a certain and determined period.*^^ 



Thus Theodoric's solution reduces simply to this, that the 

 efficient principle of gravitational motion is the first principal 

 cause in the order of nature, or, in other words, " the motion 

 of which we are treating is reducible, as to its principal cause, 

 to the essential cause of the substance of the body in motion." ®" 

 The singular merit of Theodoric's solution would appear to 

 lie in the fact that he has simplified the search for the cause 

 of gravitational motion by eliminating the generator altogether, 

 as not being in the direct line of efficient causality effecting 

 the motion. Thus he does not consider it correct to say that 

 the generator is the cause of such motion by the form he puts 

 in the falling body. This, for him, is to confuse the meta- 

 physician's way of looking at the problem with that of the 

 natural philosopher. From the point of view of the natural 

 philosopher, the generator is the motive principle in the pro- 

 duction of the body; once the body is produced, the only 

 principle of its motion that need concern him is the accidental 

 mover, which removes any impediments that might restrain 

 an efficient causality deriving directly from the principal essen- 

 tial cause of the universe. He considers further that there is 



*^ Cap. 46, T 185v: Huiusmodi igitur cause influxus non est solum in facto esse, 

 sed eciam est in fieri quodammodo, alioquin iam olim cessasset influere, et si hec 

 asset solum causa universaliter prima, tunc esse rei non clauderetur certa et deter- 

 minata peryodo. — The manuscript versions all give different readings for this chapter, 

 and none is clear and unambiguous. I give here only the reading as found in T, 

 which is the briefest and most intelligible. The English above is not a literal trans- 

 lation, but conveys what I believe to be the sense of the passage, as far as this is 

 discernible. 



*^ Cap. 46, M 18rb, T 185v, U 147rb: Motus huiusmodi de quo agitur reducitur 

 Kicut in causam principalem in causam videlicet essencialem substancie rei mote. 



