THE STUDY OF THE RELATIONS OF THINGS, y^-j 



the special senses, external impulses are conveyed to the brain, light 

 through the optical channel, sounds through the auditory nerve. But 

 at first visible things are not seen nor sounds heard. It is only by 

 numberless repetitions of like sensations that an impression is at length 

 produced. Like sensations are gradually integrated until perceptions 

 arise. As we trace onward the process by which sensations become 

 perceptions and perceptions grow to conceptions, we find that all or- 

 ders of ideas are built up out of the states of consciousness produced 

 in us by things and their relations. As I wrote, fifteen years ago : 

 We know things because, when we see, hear, touch, or taste them, the 

 present impression spontaneously blends with like impressions before 

 experienced. We know or recognize an external object, not by the 

 single impression it produces, but because that impression revives a 

 whole train or group of previous discriminations that are like or re- 

 lated to it. If something is seen, heard, felt, or tasted, which links 

 itself to no kindred idea, we say, " We do not know it " ; if it partially 

 agrees with an idea, or revives a few discriminations, we know some- 

 thing about it, and the completer the agreement the more perfect the 

 knowledge. As to know a thing is to perceive its differences from 

 other things and its likeness to other things, it is strictly an act of 

 classing. This is involved in every act of thought, for to recognize 

 a thing is to class its impression or idea with previous states of feel- 

 ing. Classification in all its aspects and applications is but the putting 

 together of things that are alike — the grouping of objects by their 

 resemblances ; and as to know a thing is to know that it is like tJiis 

 or that, to know what it is like and what it is unlike we begin to 

 classify as soon as we begin to think. 



In early infancy, when the mind is first making the acquaintance of 

 outward things, mental growth consists essentially in the production of 

 new ideas by means of repetitions of sense-impressions, and in this pro- 

 cess the pre-established relations among the cells and fibers of the 

 brain are of the greatest possible moment. The organized and semi- 

 organized groups of relations among the cerebral elements can give 

 no knowledge until the special groups of relations to which they cor- 

 respond have been presented to the consciousness by means of the 

 child's daily and hourly experience of objects and activities. The at- 

 tributes of size, color, weight, transparency, roughness, hardness, fluid- 

 ity, warmth, taste, and various other properties of solid and liquid 

 substances, and the aspects of people and domestic animals, are noted. 

 Ideas of all the common objects of the house, the grounds, the walks, 

 the drives, are soon formed and associated with words that denote them. 

 Through its spontaneous activity it has hit upon those special co-ordi- 

 nations of movement required in creeping, walking, holding things, and 

 the like, which have greatly aided in enlarging its knowledge, so that, 

 at the end of a few months, it has a store of complex conceptions, and 

 has acquired numerous aptitudes and dexterities. Hence its early 



