KNOWLEDGE. 558 KNOWLEDGE. advantage? Does it not clarify thought to have it Uinist upon our attention that wo can know- only what experience reveals? Uiiiloulilcilly ; l)ut does it not serve to confuse Ihouglil to ilesii:;nate what we cannot know as 'reality' and to call what we can know 'mere appearance'? Does not this terminology assume that there is something which we cannot know? What warrants this assump- tion? To say that W'e cannot know reality would of course be justifiable if we knew that there is such a reality, and yet knew that we never can know anything about it except that it exists. But if we never can know anything whatever about it. why call it 'reality' — a term which con- notes value? If all that is meant is that if there is anything which can never present itself in ex- perience, we can never know it. then this meaning is not clearly expressed by saying that we can know appearance, but not reality. For whether we will or not, the ))opular idea of reality as something better, more secure, more valuable than ap])earance clings to the word, and by con- trast depreciates the conception of ap]X'arance. But we may go further, and say that there is no justification in assuming the possibility of such an inexperienceable object. The assumption has no meaning. All of oir conceptions are obtained from experience, and all of our words are words that have significance only when applied to ob- jects of experience or to objects conceived of as experienceable. For instance, the word 'exist- ence' has a very definite niea'iiing. To exist is to be part of experience, or to be in some way or other related to a part of experience. Horses exist as parts of our experience. Any as yet invisible star exists as related in some way to what we do know. And 'to be related' is also a term which has meaning only when used of cer- tain connections obtaining in experience. The relation of cause and efl'ect. for example, is a delinite sort of coiuiection rwognized as existing between one experienced oliject and another. We can extend it to cimnections between ol)jects not yet experienced, provided we think of them as jiossible objects of experience. But when one of the terms of the predicated relation is asserted to be inexperienceable. tlicn the relation itself has no meaning. Tims we .see that to assert existence of any- thing that is at the same time said to he not a Jiossible object of experience is simply to vise winds without meaning. Agnosticism, or the doctrine that we cannot know reality, and skep- ticism, or the doctrine that we must ever doubt whether we can know reality, are therefore both meaningless doctrines, because reriUty as used in these doctrines has no meaning. The theory of phenomenalism is open to the same objection if it is an assertion that knowledge is limitrd to phenomen.i or appearances, with an implication that it cannot coniprehend reality. But if all 1h:it phenomenalism stands for is the view that all reality is to be defined as either actual or possible presentation to consciousness, or any discoverable relation between such presentations,
- ind that beyond such presentation there is noth-
ing conceivable except pnftxihle presentations, then phenomenalism is tenable. Finding, then, that a reality opposed to all ap ])earan<'e is unthinkable, let us examine the view that all knowledge is of appearances. May there not be a skepticism possible here? The argument for it could be stated as follows: "Everv sense may deceive; thought may be fallacious; but as sense and thought are our instruments of knowledge, we can never know anything." It takes but little logical acumen to detect the fal- lacy of such an argument. A sense deceives us when it misleads us in our expectations with regard to other senses. We can say that it misleads only when we have a test for its accu- racy or inaccuracy; this test we have in the con- sistency of our sense-perceptions. It is not justi- fiable to say that each sense ma' deceive, and that therefore all, when consistent and harmoni- ous in their presentations, may deceive. This is an example of the fallacy of composition. (See Fallacy.) This is what in substan<-e was argvied I)y the tropes of Agripjia, mentioned above. Against such sophistry we must say that before we can impeach any perception or judgment we nuist know that it tails to conform to the stand- ard. Thus knowledge is presupposed in all acknowledged ignorance, and skc])ti<'ism is an acknow ledged ignorance. Thus far we have shown that a thinker must know at least something in order to indulge liimsclf in a reasonable doubt, and that what he knows is a part at least of what finds itself in his experience. Universal skepticism and agnosticism have been shown to be untenable. Experience there undoubtedly is, and within lliat ex|ierience thiMc undoubtedly is knowledge of reality, if reality is to have any eonceival)le meaning. Now the business of the epistcmologist is to investigate this knowledge that actually exists. Tlie epistcmologist can do this successfully only by fiillowing scientific method. This means that lie nuist coini)are one act of knowledge with an- other, in order to discover what knowledge really is. He nnist not start out with some theory of his own and make the facts adjust themselve,s to this theory. Now. one fact that is characteristic of all valu- able knowledge is the fact of generalization. Every nmir thinker is constantly generalizing his knowledge. The ame is true of scientific thinkers. No science is merely descriptive in the sense that it confines itself to the ascertainment and the bare statement of facts and relations actually experienced at any one time. Whether justifiably or not, the scientist always assumes that if he can only state facts as they really are at any one time, he has a statement that is valid for all time when like conditions prevail. For in- stance, the discovery that under a definite atmos- pheric inessure pure water freezes when the ther- mometer stands at 32° F. is, for plain man and scientist alike, of significance not only as reveal- ing an isolated fact of experience tnic at the time of the discovery, but as giving a 'law.' This law is the further fact that inider like atmospheric pressure equally [lure water freezes when in a similarly constructed thermometer the mercury registers :?2'. Every statement of known fact can thus be generalized, and if when generalized it proves untrue, then the assumption of knowl- edge at the outset was unjustifiable. This is why careful scientists demand that an experi- ment should be reix-ated for verification. To verify an experiment means to ascertain its cor rectness. Obviously, however, one cannot go back in time and live over again the identical ex]X!ri- encc in order to verify the descriptive statement of it. All that can lie done is to put one's self under like conditions and then to see whether
