Dr. E. J. Mills on the Atomic Theory. 121 



and that such lesser ones are in the greater which they mea- 

 sure, as parts in a whole ; and that the whole by comprehending 

 those parts, is a mere capacity to be divided into them ; we con- 

 clude, That Quantity or Bignesse is nothing else but divisibility ; 

 and that a thing is big, by having a capacity to be divided, or 

 (which is the same) to have parts made of it. 



" This is yet more evident (if more may be) in Discrete 

 Quantity (that is, in number) then in continued Quantity, or ex- 

 tension. For if we consider any number whatsoever, we shall 

 find the essence of it consisteth in a capacity of being resolved 

 and divided into so many unities, as are contained in it ; which 

 are the parts of it. And this species of Quantity being simpler 

 than the other, serveth for a rule to determine it by : as we 

 may observe in the familiar answers to questions of continued 

 Quantity, which expresse by number the content of it : as when 

 one delivereth the Quantity of a piece of ground, by such a 

 number of furlongs, acres, perches, or the like." 



Having thus ascertained, with his customary acuteness, the 

 nature of quantity and two of its species, Digby proceeds to dis- 

 cuss a point which underlies the entire atomic controversy, 

 namely, does quantity consist of parts, or is it one ? 



"Ells, feet, inches, are no more reall Entities in the whole that 

 is measured by them, and that maketh impressions of such 

 notions in our understanding ; then .... colour, figure, mel- 

 lownesse, tast, and the like, are several substances in the apple 

 that affecteth our several senses with such various impres- 

 sions. It is but one whole, that may indeed be cut into so 

 many several! parts : but those parts are not really there till by 

 division they are parcelled out : and then the whole (out of 

 which they are made) ceaseth to be any longer : and the parts 

 succeed in lieu of it ; and are every one of them a new whole. 



" This truth is evident out of the very definition we have ga- 

 thered of Quantity. For since it is divisibility (that is, a bare 

 capacity to division) it followeth, that it is not yet divided : and 

 consequently, that those parts are not yet in it which may be 

 made of it; for division, is the making two or more things 

 of one." 



The next step is to point out that if parts be considered to 

 exist in quantity, this must consist of points or indivisibles, 

 " which we shall prove to be impossible." For if quantity were 

 divided into all the parts into which it is divisible, it would be 

 divided into indivisibles ; inasmuch as nothing divisible, and not 

 divided, would remain in it. And as all these parts are actually 

 in quantity, quantity must consist of indivisibles. None of 

 these parts has any necessary claim to be distinguished from 

 the others so as to remain divisible while they become indivisible ; 



