The educational screen (c1922-c1956])

September, 1923 Visual Instruction Association of America 339 on the other hand, is universal, general, absolute. Either there is violet ray or there is not, however it may appear to you and me. Either two is more than one or it is not; even though I may see two where you see one, or might have done before prohibition. Even Mr. Einstein, I fancy, does not wish to sweep us altogether away from this bit of intellectual terra firma. The relativity of sensation, perception, ' conception, knowledge, should only emphasize the necessity of postulating about absolute verity somewhere." This paragraph was introductory to a warning note, namely, that in our study of the learning process, we should never lose sight of the fact that our duty as teachers is not the imparting of information, is not merely to teach the child how to acquire knowledge, but consists, primarily, rather in leading the child's spirit, out into the discovery of some phase of eternal, immutable truth, through the maze of relative and often illusory data which the senses supply. With this reservation in mind, we can safely posit the theorem that the child's knowledge of the world about it comes to it chiefly through the senses and in large and controlling measure through the sense of vision. The process by which mere sensory impressions are translated into knowledge, however. is a complex one. Accordingly as advocates of a methodology of which the very cornerstone is the substitution of direct sense-impressions for linguistic symbols, we cannot too often or too sedulously examine and re-examine the various steps of that process. We shall ask the reader to bear with us, therefore, during two or three brief chapters, while we retrace, from the standpoint of our own peculiar problems, the pathway from sensation to knowledge. Now, in retracing this pathway, it is not so much our purpose to review certain general and generally accepted psychological principles or maxims, as to seek through such a review some definite indications as to how visual instruction may best be applied to certain phases of the teaching process, or as to what form of visual instruction is best adapted to certain stages of the child's psychological development. Let me illustrate what I mean. It will be found that psychologists are pretty generally agreed that the process of acquiring knowledge divides itself into certain more or less readily distinguishable stages or phases. Also the student of psychology will find these several successive stages, with some little variation, pretty generally enumerated as follows: — 1. Sensation. 2. Perception. 3. Memory, 4. Imagination. 5. Conception. A fact not always made quite so clear, but. still pretty generally accepted or implied, and certainly a fact very easy of demonstration, is that each of these stages or phases has its own characteristic accompanying emotional state and results in its own characteristic efferent impulse. In short, no single mental act or state but is tri-une in its very essence. Accompanying each purely psychological reaction, some particular state of feeling will be excited. Equally, some impulse to action will be engendered, which may be responded to. frustrated or inhibited, but which will always be there, whether consciously noted or not. Thus, mere sensation results in a state which is frequently spoken of as if it were a mental state but which is purely emotional, namely, attention. At the first dawning of a percept, however, attention merges in interest; and the retention, recall and comparison of percepts, which we shall call memory, whips interest into curiosity. Again, mere sensation results only in an efferent impulse to locomotion, while the dawning of a percept impels to manipulation. Arrest the attention of the child, or of an adult for that matter, by mere light or sound and you will succeed only in setting him, or some portion of his anatomy into instinctive motion. Definitize these sensory impressions into a clear percept, a recognizable object, and his first impulse — if he is near enough to nature— will be to touch and handle. More of this anon. For the present we have proceeded far enough along this pathway, to make a point which is of first importance. It is a point to which teachers and educators generally have given all too little attention. That point is, that most of the learning of the child's earlier years is confined to the first three stages named above— sensation, perception, memory. We do not mean to assert that a child, even a very young child, has no mental processes beyond these three phases. Of course he does. Nevertheless, by far the greater part of his