194 W. A. WALLACE 



Certain accidents or qualities are in elements as they are parts of 

 the universe, namely, gravity and levity, and, deriving from these, 

 natural motions either to or from its center. . . , Through such 

 motions bodies arc disposed in their proper places in the material 

 universe, considering the latter quantitatively in its extensive and 

 dimensional integrity as well as in its specific diversity. Such acci- 

 dents are in elements as parts of the universe, making up the uni- 

 verse precisely as actual, for actual parts are those which have a 

 species. Thus it is that gravity and levity are first found in 

 [elemental] bodies complete according to species, and that they are 

 their very first accidents as parts of the universe. . . . Wherefore, 

 if there be any bodies or natures simpler than these, of which the 

 forementioned elements might in turn be composed, light and 

 heavy would not be proper to such bodies or natures, nor would 

 these be parts of the universe specifically and quantitatively, except 

 possibly in an originative way.^^ 



Gravity, then, is one of the first qualities of bodies considered 

 in relation to other bodies making up the universe, and is 

 properly attributable to the elemental constituents of such 

 bodies, themselves specifically complete, as the ultimate source 

 of their natural or gravitational motions. This suggests for 

 Theodoric some observations as to whether gravity is an abso- 

 lute quality, or merely relative, and whether it is subject to 

 intensification or not. Surprisingly enough, such questions were 

 not commonly discussed at the turn of the fourteenth century; 

 Ciagett has pointed out that the first evidence of the concept 

 " specific weight " is only to be found in the pseudo-Archi- 

 medean treatise De insidentibus in humidum, itself dating from 

 the thirteenth.^- There is no direct use by Theodoric of the 

 quantitative notions found in De insidentibus, but he does 

 speak of an " intensity " of gravity, as is clear from the 

 folio win 2: citation: 



*& 



There is a twofold modality of heavy and light. One is according to 

 absolute quality, w^hose formality consists in this, that heavy and 

 light are principles of a determinate tendency to some place in the 

 universe. Under this formality heavy and light are distinguished in 

 bodies in the following way, viz., some are heavy and light simply, 



" Ibid., pp. 329-330. " Op. dt., pp. 93-95, 674. 



