But, in determining the shape of a thing, an act of judgment is necessary. This may be illustrated by the example of a hoop, which in one position will make a picture in the eye which is circular, in another position the picture of it will be oval, and in another only a straight line. If a person will observe a hoop in these different positions, and then attempt to draw a picture of it, he will be conscious of this varying picture in the eye. Of course, in order to decide the shape of a thing, we must decide its distance, its relative position, and various circumstances which would alter the form of the picture in the eye. It is only by long experience that the infant child gradually acquires the power of determining the shape, size, and distance of objects.
The painter's art consists in laying on to canvas an enlarged picture of the scene which is painted in the interior of his own eye. In this minute picture of the eye, the more distant an object the smaller its size, the more indistinct its outline, and the fainter its colors. These same are transferred to canvas in an enlarged form; the distant objects are made small in size, faint in colors, and indistinct in outline, just in proportion to their distance.
The organ of vision is the inlet of more enjoyment to the mind than any of the other senses. Through this small loop-hole the spirit looks forth on the rich landscape of nature, and the charms both of the natural and moral world. The fresh colors, the beauty of motion, the grace of figures, the fitness of proportion, and all the charms of taste, are discovered through this medium. By the eye, also, we learn to read the speaking face of man, we greet the smile of friendship and love, and all those varying charms that glance across the human face divine. By the aid of this little organ, too, we climb not only the summits of earth's domains, but wander forth to planets, stars, and suns, traverse the vast ethereal expanse, and gather faint images and flitting visions of the spirit's future home.
CHAPTER X.
CONCEPTION AND MEMORY.
There has been much speculation on the question as to whether the mind possesses any ideas entirely independent of the senses, which were gained without any aid or influence from them. Many have maintained the existence of some ideas, which they denominate innate ideas, which they suppose were originally implanted in the mind, and not at all dependent on sensation.
On this subject it may be sufficient to remark that there is no proof of the existence of any such ideas. All ideas, so far as we can trace them, seem to have been originally gained by the senses, though the mind has the power of making new arrangements and combinations of such materials as are thus furnished.
The intuitive truths seem to exist as a part of the original constitution of the mind, but there is no evidence that they would ever have been called into exercise except through the instrumentality of the senses.
There is nothing to prove that the positive exercise of thought, feeling, and volition is necessary to the existence of mind, and no proof that the mind might not have existed forever without thought or feeling of any kind, were it not for the aid of the senses. We know that there are periods of sleep and of swooning, when the mind is in existence, and yet when there is no evidence that either thoughts, feelings, or volitions are in exercise.
Speculations on this subject seem to be profitless, because there are no data for determining them. The facts in the case are not of a character to enable us to pronounce positively either that these operations are or are not essential to its existence. It may be that in sleep and in a swoon these phenomena exist, and no memory is retained of them, and it is equally probable that at such intervals all mental operations entirely cease.