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7. State and explain the quotation from Ward.

8. What do the senses tell us of objects?

9. What do they seem to tell us?

10. State the three questions which a theory of perception has to

answer.

SUGGESTIVE QUESTIONS.

1. If the first sensation is not known, how can the knowledge of sensations originate?

2. Is the assertion, knowledge begins with sensation, equivalent to all our ideas were derived from sensations? If not, what is the

difference?

3. What is the meaning of the terms, sensationalist, empiricist, transcendentalist?

LESSON XXIII.

PERCEPTION.

(Continued.)

We saw in the last lesson that what the senses really tell us of objects is how they affect us-the sensations produced by them in our minds-but that they seem to tell us of objects themselves as having certain qualities, and occupying a certain place.

What the Mind Does when it Perceives. What does the mind do to its sensations of color and smell and taste in order to perceive colors, odors, and tastes as qualities of objects? It groups them together, does it not? When you look at an apple, you group its color, taste, and smell together as qualities of one object. Sully puts it as follows: "Sense-impressions" - he means sensations—“are the alphabet by which we spell out the objects presented to us. In order to grasp or apprehend these objects, these letters must be put together after the manner of words. Thus the apprehension of an apple by the eye involves the putting together of various sensations of sight, touch, and taste. This is the mind's own work, and is known as perception." He compares sensations to the letters of the alphabet; and precisely as in reading we put the letters b, r, i, c, k together and read "brick," so, in per

ceiving, we put together certain sensations and thus gain a knowledge of objects.

But this grouping of sensations together is not all we do when we perceive. As long as your sensations seem to be sensations, you do not perceive. You perceive only when they seem to be what we have seen they are hot qualities actually forming a part of the objects in the world about us, or states of our own bodies.

To perceive, then, is to group sensations together and regard them as qualities of external objects. But is that entirely accurate? When we perceive an apple by the sense of sight, we group the sensation of color with recollections of past sensations — taste, smell, feeling of mellowness, etc.—do we not? Strictly speaking, then, what we do when we perceive is to make a group consisting of one or more sensations, and ideas of sensations, and regard the group as qualities of an external object.

The state of mind that results from perception is called a percept. We must be careful not to confuse this with image. While you are looking at an apple, your state of mind is a percept; when you turn your head away and think about it, the picture that you form of it is an image.

In order to reach a percept, the mind must take three steps: (1) it must be conscious of a definite sensation; (2) it must group this sensation with images of sensations. already experienced; and (3) it must think of these sensations as qualities of objects having a more or less definite position in space.

To explain the problem of perception, then, is to explain how the mind comes to take these three steps.

I have no intention of attempting to explain perception. It is universally conceded to be one of the most difficult

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THE MIND AND DEFINITE SENSATIONS.

217

subjects in Psychology. My purpose will be accomplished if we can get a definite idea of the problem that a theory of perception undertakes to solve, and some general idea of what seems to be the true solution.

Perhaps it will be more convenient to consider the problem of perception in the form in which it was stated in the last lesson, although the two forms are in fact identical, as a little consideration will enable us to see.

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How the Mind Becomes Conscious of Definite Sensations. (1) How is it that the mind becomes conscious of definite sensations that unindividualized sensations come to be individualized, and known as such and such sensations? That question our study of attention enables us to answer. If a child's experience consisted entirely of sensations of sound, it is easy to see that the loudest those having the character of greatest intensity — would be sure to be attended to in the course of time. They would stand out in the foreground of his consciousness would be individualized and thus lose the indefiniteness that characterizes a child's experiences in the beginnings of its mental life. Evidently, also, the pleasurable or painful character of its experiences would have the same effect, since it is likewise a cause of attention.

How Sensations Become Localized. (2) How is it that these sensations become localized-projected into our bodies and into the external world? Very young children evidently do not localize their sensations. When painful operations are performed upon them, their hands do not need to be held, since they do not know where the pain is. How do they finally come to get this knowledge?

The Local Sign.

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Whether your little finger is pinched, or touched, or burned, or bruised, or cut, you locate the sensation in it you know that it is your little finger that is affected. How is it that you are able to do this? How is it that when such different sensations as those of a mere touch, a burn, a bruise, a cut, a pinch, report themselves to consciousness, you are able to refer them all to the same place? Precisely as you can tell what country an Irishman comes from as soon as you hear him talk. There are tall Irishmen and short Irishmen, stout Irishmen and lean Irishmen, Irishmen that are handsome and Irishmen that are homely; but, no matter how widely they differ in appearance, as soon as you hear one talk you know that he hails from the land of Erin. And precisely as the brogue of an Irishman enables you, as soon as you hear him speak, to tell his nationality, so, since we are able to locate in the same place the various sensations that arise in connection with the little finger, those sensations must have some characteristic in common. A mere touch, a burn, a bruise, a cut, a pinch, differing as widely as they do, could not be referred to the same place if they did not speak a language that betrayed their origin. The characteristic of our sensations—the brogue which betrays their origin — by means of which we are able to locate them, first in our bodies, and some of them afterwards in the external world, is called the local sign.

How Local Signs are Apprehended as Signs of Place. But perhaps the first time you noticed the brogue of an Irishman you did not know what country he came from. If you had noticed it in a dozen or fifty people, without knowing they were from Ireland, you would not have

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