CHAPTER I. SENSE-PERCEPTION. THE Presentative Faculties are those powers of the mind by which knowledge comes to us directly from simple observation. They are subdivided into Sense-Per- Presentative ception, and what is popularly called Consciousness, faculties but more properly the Inner-Sense. The former gives us cognitions of the world of matter, the latter of the world of mind. described. How can the soul come into communi cation with the external world? One of the great questions of Psychology is, How does the soul come into communication with the outer world? How can immaterial mind come into relations with material substance, so that the former shall receive impressions from the latter? The answers to this question have been various. Like most other subjects pertaining to our constitution and relations, it is involved in more or less of mystery. It is not likely that this mystery, under present human limitations, will ever be absolutely cleared up. But we can at least trace the outlines of the process, and note a considerable proportion of the attendant phenomena. We observe, first, that there are several bodily organs and instrumentalities concerned in this process. To begin at the outer surface, we find the organs of sight, of hearing, of smelling, of tasting, and of touch. Certain qualities or properties of matter affect these in The senses. organs. The senso rium. ways corresponding to the constitution of the several We next observe that these organs are all intimately connected with what is called the Sensorium. This consists of the brain, spinal column, and a system of nerves running from these to every minute part of the surface of the body, and to most of the internal points. When any outward object or quality makes an impression upon its corresponding sense, it affects one of the nerves, which is so nearly like a telegraphic wire that through it an effect is instantly proWe cannot trace this series of physical Result of sensation. duced in the brain. effects any further. We only know that with the vibration of the nerve and the effect on the brain, there comes a change in the mind; we know ourselves to be in a new state. We say we are sensible of it, or conscious of it, and that is all we immediately know. Sensation a This is what we call a Sensation, and the general name by which we designate this whole class of changes thus produced in the mind is Sensations. Thus, if a rose state of mind. is brought near us for the first time, even if we are not able to see it, the odor given off from it somehow affects the olfactory nerve, and produces a peculiar state of mind. We apprehend this change by the Inner-Sense, but this is all that we at first know. We are not, on the supposition we are now making, aware that there is any outward object that causes it. The effect, so far as appears, may have been produced by some internal cause. So if, for the first time, we hear the music of an organ, the only cognition we have is of a state of mind, and we do not know that it comes from without. It is only after some experience, and the combined action of our senses, that we learn to refer these states of mind, Perception. or internal changes, to some object in the external world. Here we have Perception. We wish to get a clear distinction between Sensation and Perception, and, as well, the exact relation of the two processes. Sensation is a state of mind produced by some external object or influence operating upon the sensorium, and is immediately successive to a change in some organ of sense. Perception is an act or process of the and percepmind immediately successive to a sensation, by which we refer this sensation to something external as its cause. Sensation tion defined. Sensation subjective. Perception It is sometimes said that Sensation is subjective, and Perception objective. But this needs qualification. Perception, as well as Sensation, is subjective; but the knowledge we get by perception is of external, outer, or objective things, while Sensation objective. is exclusively subjective, and implies no knowledge of externality. Dr. Hopkins says that Sensation is a movement from without inward, Perception is a movement from within outward. |