GRAVITATIONAL MOTION 193 



Theodoric's complete doctrine on this subject. It is not my 

 intention to enter into a detailed analysis of the doctrine 

 presented, but rather to sketch the essential content of The- 

 odoric's teaching, supporting this by substantial citation from 

 the manuscript versions of the opusculum. In thus utilizing 

 the space alloted to me, I also forego the opportunity to point 

 out possible relationships between Theodoric's doctrine and 

 more recent thought on gravitation. I trust, however, that 

 the material presented will have some bearing on further 

 analyses of the causes of gravitational motion that may be 

 forthcoming from Thomistic philosophers. 



Gravity and the Elements 



The elements, for Theodoric, are material components of 

 natural bodies, " principles according to the formality of 

 matter," or, more explicitly, " whence a thing is materially 

 composed." ^ As such, they can be studied by the meta- 

 physician, who is interested in them " from the viewpoint of 

 their substance, how they pertain to the genus of being pre- 

 cisely as being," or they can be studied by the natural phi- 

 losopher " insofar as they are natural bodies and accordingly 

 related to motion and change." ^ The latter consideration again 

 permits of a twofold division, for the natural philosopher may 

 investigate them in a way similar to that of the modem 

 physicist, insofar as they are " the first parts of the universe," 

 or in a way similar to that of the modern chemist, insofar as 

 they contain a " principle of transformation by which one 

 element can be simply generated from another, or compounds 

 formed from elements." " Gravity is of primary interest to the 

 physicist, thus characterized, as Theodoric explains in the 

 following passage: 



cated with the foliation. I have already furnished a critical Latin edition of the 

 prologue and first eight chapters of this opusculum in my Scientific Methodology, 

 pp. 324-331. 



® Prologue, (ed. Wallace) pp. 324-325. 



* Cap. 7, p. 329. 



" Ibid. 



