would imply an unlimited power of comprehension in the human mind, which is impossible. All particular things consist of, and lead to an infinite number of other things. Abstraction is a consequence of the limitation of the comprehensive faculty, and mixes itself more or less with every act of the mind of whatever kind, and in every moment of its existence. There is no idea of an individual object, which consists of a single impression, but of a number of impressions massed together: there is no idea of a particular quality of an object, which is perfectly simple, or which is not the result of a number of impressions of the same sort classed together by the mind without attending to their particular differences. Every idea of an object is, therefore, in a strict sense an imperfect and general notion of an aggregate: of a house, or tree, as well of a city, or forest: of a grain of sand as well as of the universe. Every idea of a sensible quality, as of the whiteness of the sheet of paper before me, or the hardness of the table on which I lean, implies the same power of generalization, of connecting several impressions into one sort, as the most refined and abstract idea of virtue and justice, of motion, or extension, or space of time, or being itself. This view of the subject is not, I confess, very obvious at first sight, and it will be more easily understood after I have stated the arguments of others on this difficult question. The concise account of the nature of abstract ideas is that which Mr. Locke has given, is as follows. "All things that exist being particular, it may be perhaps thought reasonable that words which ought to be conformed to things should be so too, I mean in their signification: but yet we find the quite contrary. The far greatest part of words that make all languages are general terms, which has not been the
