SCIENCE A COLLECTION OF AGGREGATES. 107 



which Logic expresses its propositions, are symbols that do 

 not profess to represent things, properties, or powers, of one 

 kind more than another ; and may equally well stand for the 

 attributes belonging to members of some connected series of 

 ideal curves which have never been drawn, as for so many 

 real objects. And the theorems of Geometry, so far from 

 contemplating perceptible lines and surfaces as elements in 

 the truths enunciated, consider these truths as becoming 

 absolute only when such lines and surfaces become ideal 

 only when the conception of something exercising force is 

 extruded. 



Let me now make a second re-statement, not implying 

 acceptance of the doctrine of Evolution, but exhibiting with 

 a clearness almost if not quite as great, these fundamental 

 distinctions. 



The concrete sciences, taken together or separately, con 

 template as their subject-matters, aggregates cither the entire 

 aggregate of sensible existences, or some secondary aggre 

 gate separable from this entire aggregate, or some tertiary 

 aggregate separable from this, and so on. Sidereal Astro 

 nomy occupies itself with the totality of visible masses dis 

 tributed through space; which it deals with as made up of 

 identifiable individuals occupying specified places, and seve 

 rally standing towards one another, towards sub-groups, and 

 towards the entire group, in defined ways. Planetary Astro 

 nomy, cutting out of this all-including aggregate that 

 relatively minute part constituting the Solar System, deals 

 with this as a whole observes, measures, and calculates the 

 sizes, shapes, distances, motions, of its primary, secondary, 

 and tertiary members ; and, taking for its larger inquiries 

 the mutual actions of all these members as parts of a co 

 ordinated assemblage, takes for its smaller inquiries the 

 actions of each member considered as an individual, having 

 a set of intrinsic activities that are modified by a set of 



