KNOWLEDGE. 557 KNOWLEDGE. pass our hands down tlic length of it and find that it feels straight although it looks crooked. We now lean on it. It 1hmi> our weiglit just as we liave learned that straight-lookinfj sticks do. Is the stick broken or not? We naturally an- swer: It seems to be broken, but really it is not. The broken appearance is an illusion. Now, what is the nieaninj,' of this answer? The most obvious nieaninjf is, doubtless, the true one, as is suggested 1>.V the etyniology of the word 'illusion.' The l)roken appearance fools us; if we proceed on the supposititju that it is broken we are disappointed. If. however, we proceed nil the opposite sU|)posilioii. we find that the event conforms to our expectation. The real qualities of the stick are those which do not de- ceive us when we want to use it. The stick is really straight, because we can use it as we use straight sticks: we cannot u.se it as we do broken ones. Hence its brokenness is an illu- sion. In other words, the distinction between reality and appearance is at iirst a practical distinction. At this stage the two correlative categories are reality and illusion: if 'appearance' )s used it means 'illusion.' The ini]X)rtant thing is that not evcrii experience is an appearance. Only those experiences that fool us are not real. But after a while another stage of development is reached. It comes, for instance, to lie noticed that a thin disk presents a circular outline when in one position, an oval outline when in another: it even has a rectilinear outline at times. None of these different qualities of outline is apt to deceive a keen observer who has had considerable experience. Hence in the preceding stage they were not called illusions. But now attention gets' directed to this jx^culiar variability of the qualities of objects. Which of these variations is the real quality? Obviously again the one which is the basis for our calculations in our dealings with the object. The disk therefore is circular, though it looks oval or rectilinear. These various appearances are not illusions, be- cause they do not usually fool us, but they are not real in the sense that they are variations from the qualities which the usable object has. Appearance in this connection might be defined as a quality not itself real in the sense of be- longing to the usable object : but also not neces- sarily illusory. Our eyes do not always see the object as it is. but still they do not deceive us. What we do see helps us to infer what we do not see, or the real quality. This real quality, however, can I)c seen if we put ourselves in the proper condition. For instance, the disk does have a visible circular outline if we hold it at right angles to our line of vision. Otherwise its outline, which in virion is elliptical or otherwise, is interpreted in thought as circular. But it is quite natural that this distinction be- tween reality and ap])carance should not long satisfy. A further distinction is suggested by some such aigumcnt as the following: If our sense of sight can present an object in some other form than that which it really has. how can we tell when its presentations are real or merely ap- parent? If the oval shape of the disk is merely an apparent shape, why may not the circular and every other shape be apparent also? In short, can our senses give us any other knowledge ex- cept that of appearances? It is clear that such a question involves a change in the meaning of reality, which has hitherto had a practical rather than a theoretical significance. Tliis change ap- pears to be forced on us, when we have our at- tention called to the fact that all our senses may deceive us. So long as it is our sense of sight that presents objects not as they really are, we can find what they are by appealing to the other .senses. Reality is still a sensible thing. But what if eveiy sense stands on the same foot- ing with sight? Can one any longer appeal from sense to sense when every sense may give us only appearance? Must not reality be something supersensible? And if thought may miscarry, as it often does, must we not say that reality tran- scends even thought? Then how can we know that we know anything about it ? The discovery of the fallibility of every sense and of thought is the beginning of philosophic sorrow. The doctrine of the relativity (q.v. ) of our knowledge begins to prevail. Historically there have been two different consequences of this doctrin?. A thinker may either bold to the no- tion of a reality opposed tii appearance, or he may find it so shadowy and unwarrantable a con- ception that he gives it up altogether. Let u.s consider the former case, where the thinker gets into difficulty by being unable to say what real- ity really is." The difficulty is for him insoluble, because h,^ fails to see that he is trying to make a distinction to which no actually known differ- ence corresponds. He is employing the cate- gories of appearance and reality beyond their proper limits. The relation between appearance and reality was first recognized as holding be- tween actually experienced qualities. Gradually the apparent qualities encroached on the pre- serves of the real, imtil at last all real qualities were entirelv ousted from the region of experi- ence. Or, to put the same thing in other terms, a distinction which was first made as a recogni- tion of a certain practical difference is now eni- jdoyed when that practical difference is no longer the matter in point. Tiie continued use of the distinction gets its plausibility from the fact that the terms used have clear meanings within the original limits of their application. A thinker is therefore tempted to assume that the terms still have defi- nite significance in their new sphere of applica- tion. .
example of the change of meaning in
the word 'really' as we pass from popular to chemical usage will show that it is unsafe to treat the word 'real' as if it expressed an unchanging, definite positive conception whenever used. The ordinary man of affairs would .say unhesitatingly that charcoals and diamonds are really different. The analytical chemist would be tempted to say that they are really identical. There is no contra- diction in these two statements, because 'really' for the layman means 'for the ordinary pur- poses of life.' and for the chemist it means 'from the point of view of chemical analysis.' Now. if the word 'really' can change so much when we are still within the limits of experience, is it not well to ask ourselves what it means when we go Ijeyond the limits of actual and possible experi- ence and say that apparently things are as we find fhem in our experience, hut what they really are we never shall know? 'Really' here has no positive meaning: at least it has no practical meaning. It seems merely to sene notice of an attempt to carry out a practical distinction when there is no longer any possibility of any practical advantage from it. But is there not a theoretical
