Here we see emphasized the relation to the body which has been mentioned above.  If we ask the psychologist how he knows that the body he is talking about is a real body, and not merely an imagined one, he has to fall back upon the test which is common to us all.  A real hand is one which we see with the eyes open, and which we touch with the other hand.  If our experiences of our own body had not the setting which marks all sensory experiences, we could never say:  I perceive that my body is near the desk.  When we call our body real, as contrasted with things imaginary, we recognize that this group of experiences belongs to the class described; it is given in sensation, and is not merely thought of.

It will be observed that, in distinguishing between sensations and things imaginary, we never go beyond the circle of our experiences.  We do not reach out to a something beyond or behind experiences, and say:  When such a reality is present, we may affirm that we have a sensation, and when it is not, we may call the experience imaginary.  If there were such a reality as this, it would do us little good, for since it is not supposed to be perceived directly, we should have to depend upon the sensations to prove the presence of the reality, and could not turn to the reality and ask it whether we were or were not experiencing a sensation.  The distinction between sensations and what is imaginary is an observed distinction.  It can be proved that some experiences are sensory and that some are not.  This means that, in drawing the distinction, we remain within the circle of our experiences.

There has been much unnecessary mystification touching this supposed reality behind experiences.  In the next chapter we shall see in what senses the word “reality” may properly be used, and in what sense it may not.  There is a danger in using it loosely and vaguely.

16.  MAY WE CALL “THINGS” GROUPS OF SENSATIONS?—­Now, the external world seems to the plain man to be directly given in his sense experiences.  He is willing to admit that the table in the next room, of which he is merely thinking, is known at one remove, so to speak.  But this desk here before him:  is it not known directly?  Not the mental image, the mere representative, but the desk itself, a something that is physical and not mental?

And the psychologist, whatever his theory of the relation between the mind and the world, seems to support him, at least, in so far as to maintain that in sensation the external world is known as directly as it is possible for the external world to be known, and that one can get no more of it than is presented in sensation.  If a sense is lacking, an aspect of the world as given is also lacking; if a sense is defective, as in the color-blind, the defect is reflected in the world upon which one gazes.