one uses the idea--that is to say, the present facts projected into a whole in the light of absent facts--as a guide of action. Suppose, by means of its specifications, one works one's way along until one comes upon familiar ground--finds one's self. _Now_, one may say, my idea was right, it was in accord with facts; it agrees with reality. That is, acted upon sincerely, it has led to the desired conclusion; it has, _through action_, worked out the state of things which it contemplated or intended. The agreement, correspondence, is between purpose, plan, and its own execution, fulfillment; between a map of a course constructed for the sake of guiding behavior and the result attained in acting upon the indications of the map. Just how does such agreement differ from success?
III If we exclude acting upon the idea, no conceivable amount or kind of intellectualistic procedure can confirm or refute an idea, or throw any light upon its validity. How does the non-pragmatic view consider that verification takes place? Does it suppose that we first look a long while at the facts and then a long time at the idea, until by some magical process the degree and kind of their agreement become visible? Unless there is some such conception as this, what conception of agreement is possible except the experimental or practical one? And if it be admitted that verification involves action, how can that action be relevant to the truth of an idea, unless the idea is itself already relevant to action? If by acting in accordance with the experimental definition of facts, viz., as obstacles and conditions, and the experimental definition of the end or intent, viz., as plan and method of action, a harmonized situation effectually presents itself, we have the adequate and the only conceivable verification of the intellectual factors. If the action indicated be carried out and the disordered or disturbed situation persists, then we have not merely confuted the tentative positions of intelligence, but we have in the very process of acting introduced new data and eliminated some of the old ones, and thus afforded an opportunity for the resurvey of the facts and the revision of the plan of action. By acting faithfully upon an inadequate reflective presentation, we have at least secured the elements for its improvement. This, of course, gives no absolute guaranty that the reflection will at any time be so performed as to prove its validity in fact. But the self-rectification of intellectual content through acting upon it in good faith is the "absolute" of knowledge, loyalty to which is the religion of intellect.
The intellectual definition or delimitation assigned to the "given" is thus as tentative and experimental as that ascribed to the idea. In form both are categorical, and in content both are hypothetical. Facts really exist just as facts, and meanings exist as meanings. One is no more superfluous, more subjective, or less necessitated than the other. In and of themselves as existences both are equally realistic and compulsive. But on the basis of existence, there is no element in either which may be strictly described as intellectual or cognitional.
There is only a practical situation in its brute and unrationalized form. What is uncertain about the facts as given at any moment is whether the right exclusions and selections have been made. Since that is a question which can be decided finally only by the experimental issue, this ascription of character is itself tentative and experimental. If it works, the characterization and delineation are found to be proper ones; but every admission prior to inquiry, of unquestioned, categorical, rigid objectivity, compromises the probability that it will work. The character assigned to the datum must be taken as hypothetically as possible in order to preserve the elasticity needed for easy and prompt reconsideration. Any other procedure virtually insists that all facts and details anywhere happening to exist and happening to present themselves (all being equally real) must all be given equal status and equal weight, and that their outer ramifications and internal complexities must be indefinitely followed up. The worthlessness of this sheer accumulation of realities, its total irrelevancy, the lack of any way of judging the significance of the accumulations, are good proofs of the fallacy of any theory which ascribes objective logical content to facts wholly apart from the needs and possibilities of a situation.
The more stubbornly one maintains the _full_ reality of either his facts or his ideas, just as they stand, the more accidental is the discovery of relevantly significant facts and of valid ideas--the more accidental, the less rational, is the issue of the knowledge situation. Due progress is reasonably probable in just the degree in which the meaning, categorical in its existing imperativeness, and the fact, equally categorical in its brute coerciveness, are assigned only a provisional and tentative nature with reference to control of the situation. That this surrender of a rigid and final character for the content of knowledge on the sides both of fact and of meaning, in favor of experimental and functioning estimations, is precisely the change which has marked the development of modern from mediaeval and Greek science, seems undoubted. To learn the lesson one has only to contrast the rigidity of phenomena and conceptions in Greek thought (Platonic ideas, Aristotelian forms) with the modern experimental selection and determining of facts and experimental employment of hypotheses. The former have ceased to be ultimate realities of a nondescript sort and have become provisional data; the latter have ceased to be eternal meanings and have become working theories. The fruitful application of mathematics and the evolution of a technique of experimental inquiry have coincided with this change. That realities exist independently of their use as intellectual data, and that meanings exist apart from their utilization as hypotheses, are the permanent truths of Greek realism as against the exaggerated subjectivism of modern philosophy; but the conception that this existence is to be defined in the same way as are contents of knowledge, so that perfect being is object of perfect knowledge and imperfect being object of imperfect knowledge, is the fallacy which Greek thought projected into modern. Science has advanced in its methods in just the degree in which it has ceased to assume that prior realities and prior meanings retain fixedly and finally, when entering into reflective situations, the characters they had prior to this entrance, and in which it has realized that their very presence within the knowledge situation signifies that they have to be redefined and revalued from the standpoint of the new situation.
IV This conception does not, however, commit us to the view that there is any conscious situation which is totally non-reflective. It may be true that any experience which can properly be termed such comprises something which is _meant_ over and against what is given or there.
But there are many situations into which the rational factor--the mutual distinction and mutual reference of fact and meaning--enters only incidentally and is slurred, not accentuated. Many disturbances are relatively trivial and induce only a slight and superficial redefinition of contents. This passing tension of facts against meaning may suffice to call up and carry a wide range of meaningful facts which are quite irrelevant to the intellectual problem. Such is the case where the individual is finding his way through any field which is upon the whole familiar, and which, accordingly, requires only an occasional resurvey and revaluation at moments of slight perplexity. We may call these situations, if we will, knowledge situations (for the reflective function characteristic of knowledge is present), but so denominating them does not do away with their sharp difference from those situations in which the critical qualification of facts and definition of meanings constitute the main business. To speak of the passing attention which a traveler has occasionally to give to the indications of his proper path in a fairly familiar and beaten highway as knowledge, in just the same sense in which the deliberate inquiry of a mathematician or a chemist or a logician is knowledge, is as confusing to the real issue involved as would be the denial to it of _any_ reflective factor. If, then, one bears in mind these two considerations--(1) the unique problem and purpose of every reflective situation, and (2) the difference as to range and thoroughness of logical function in different types of reflective situations--one need have no difficulty with the doctrine that the great obstacle in the development of scientific knowing is that facts and meanings enter such situations with stubborn and alien characteristics imported from other situations.
This affords an opportunity to speak again of the logical problem to which reference and promise of return were made earlier in this paper.
Facts may be regarded as existing qualitatively and in certain spatial and temporal relations; when there is knowledge another relation is added, that of one thing meaning or signifying another. Water exists, for example, as water, in a certain place, in a certain temporal sequence. But it may signify the quenching of thirst; and this signification-relation constitutes knowledge.[57] This statement may be taken in a way congruous with the account developed in this paper.
But it may also be taken in another sense, consideration of which will serve to enforce the point regarding the tentative nature of the characterization of the given, as distinct from the intended and absent. Water means quenching thirst; it is drunk, and death follows.
It was not water, but a poison which "looked like" water. Or it is drunk, and is water, but does not quench thirst, for the drinker is in an abnormal condition and drinking water only intensifies the thirst.
Or it is drunk and quenches thirst; but it also brings on typhoid fever, being not merely water, but water plus germs. Now all these events demonstrate that error may appertain quite as much to the characterization of existing things, suggesting or suggested, as to the suggestion _qua_ suggestion. There is no ground for giving the "things" any superior reality. In these cases, indeed, it may fairly be said that the mistake is made because qualitative thing and suggested or meaning-relation were _not_ discriminated. The "signifying" force was regarded as a part of the direct quality of the given fact, quite as much as its color, liquidity, etc.; it is only in another situation that it is discriminated as a relation instead of being regarded as an element.
It is quite as true to say that a thing is called water because it suggests thirst-quenching as to say that it suggests thirst-quenching because it is characterized as water. _The knowledge function becomes prominent or dominant in the degree in which there is a conscious discrimination between the fact-relations and the meaning-relations._ And this inevitably means that the "water" ceases to be _surely_ water, just as it becomes doubtful or hypothetical whether this thing, whatever it is, really means thirst-quenching. If it really means thirst-quenching, it is water; so far as it may not mean it, it perhaps is not water. It is now just as much a question _what_ this _is_ as what it means. Whatever will resolve one question will resolve the other. In just the degree, then, in which an existence or thing gets intellectualized force or function, it becomes a fragmentary and dubious thing, to be circumscribed and described for the sake of operating as _sign_, or clue of a _future_ reality to be realized through action. Only as "reality" is reduced to a sign, and questions of its nature as sign are considered, does it get intellectual or cognitional status. The bearing of this upon the question of practical character of the distinctions of fact and idea is obvious. No one, I take it, would deny that action of some sort _does_ follow upon judgment; no one would deny that this action _does_ somehow serve to test the value of the intellectual operations upon which it follows.
But if this subsequent action is _merely_ subsequent, if the intellectual categories, operations, and distinctions are complete in themselves, without inherent reference to it, what guaranty is there that they pass into relevant action, and by what miracle does the action manage to test the worth of the idea? But if the intellectual identification and description of the thing are as tentative and instrumental as is the ascription of significance, then the exigencies of the active situation are operative in all the categories of the knowledge situation. Action is not a more or less accidental appendage or afterthought, but is undergoing development and giving direction in the entire knowledge function.
In conclusion, I remark that the ease with which the practical character of these fundamental logical categories, fact, meaning, and agreement, may be overlooked or denied is due to the organic way in which practical import is incarnate in them. It can be overlooked because it is so involved in the terms themselves that it is assumed at every turn. The pragmatist is in the position of one who is charged with denying the existence of something because, in pointing out a certain fundamental feature of it, he puts it in a strange light. Such confusion always occurs when the familiar is brought to definition.
The difficulties are more psychological--difficulties of orientation and mental adjustment--than logical, and in the long run will be done away with by our getting used to the different viewpoint, rather than by argument.
FOOTNOTES: [52] _Studies in Logical Theory_, University of Chicago Press, 1903.
[53] Mill's doctrine of the ambiguity of the copula (_Logic_, Book I, chap. IV, § 1) is an instance of one typical way of evading the problem. After insisting with proper force and clearness upon the objective character of our intellectual beliefs and propositions, viz., that when we say fire causes heat we mean actual phenomena, not our ideas of fire and heat (Book I, chap. II and chap. XI, § 1, and chap. V, § 1), he thinks to dispose of the whole problem of the "is" in judgment by saying that it is only a sign of affirmation (chap. I, § 2, and chap. IV, § 1). Of course it is. But unless the affirmation (the sign of thought) "agrees" or "corresponds with" the relations of the phenomena, what becomes of the doctrine of the objective import of propositions? How otherwise shall we maintain with Mill (and with common-sense and science) the difference between asserting "a fact of external nature" and "a fact in my mental history"?
[54] _Studies in Philosophy and Psychology_, article by Woodbridge on "The Problem of Consciousness," especially pp. 159-60.
[55] In other words, "ideas" is a term capable of assuming any definition which is logically appropriate--say, meaning. It need not have anything to do with the conception of little subjective entities or psychical stuffs.
[56] Of course, the monistic epistemologies have an advantage in the statement of the problem over the dualistic--they do not state it in terms which presuppose the impossibility of the solution.
[57] This view was originally advanced in the discussion of quite another problem than the one here discussed, viz., the problem of consciousness; and it may not be quite just to dissever it from that context. But as a formula for knowledge it has enough similarity with the one brought out in this paper to suggest further treatment; it is not intended that the results reached here shall apply to the problem of consciousness as such.
IX NAÏVE REALISM VS. PRESENTATIVE REALISM[58] I In spite of the elucidations of contemporary realists, a number of idealists continue to adduce in behalf of idealism certain facts having an obvious physical nature and explanation. The visible convergence of the railway tracks, for example, is cited as evidence that what is seen is a mental "content." Yet this convergence follows from the physical properties of light and a lens, and is physically demonstrated in a camera. Is the photograph, then, to be conceived as a psychical somewhat? That the time of the visibility of a light does not coincide with the time at which a distant body emitted the light is employed to support a similar idealistic conclusion, in spite of the fact that the exact difference in time may be deduced from a physical property of light--its rate. The dislocation in space of the light seen and the astronomical star is used as evidence of the mental nature of the former, though the exact angular difference is a matter of simple computation from purely physical data. The doubling of images of, say, the finger when the eyeball is pressed, is frequently proffered as a clincher. Yet it is a simple matter to take any body that reflects light, and by a suitable arrangement of lenses to produce not only two but many images, projected into space. If the fact that under definite _physical_ conditions (misplacement of lenses), a finger yields two images proves the psychical character of the latter, then the fact that under certain conditions a sounding body yields one or more echoes is, by parity of reasoning, proof that the echo is made of mental stuff.[59] If, once more, the differences in form and color of a table to different observers, occupying different physical positions, is proof that what each sees is a psychical, private, isolated somewhat, then the fact that one and the same physical body has different effects upon, or relations with, different physical media is proof of the mental nature of these effects. Take a lump of wax and subject it to the same heat, located at different positions; now the wax is solid, now liquid--it might even be gaseous. How "psychical" these phenomena!
It almost seems as if the transformation of the physical into the mental in the cases cited exemplifies an interesting psychological phenomenon. In each case the beginning is with a real and physical existence. Taking "the real object," the astronomical star, on the basis of its physical reality, the idealist concludes to a psychical object, radically different! Taking the _single_ object, the finger, from the premise of its real singleness, he concludes to a double mental content, which then takes the place of the original single thing! Taking one-and-the-same-object, the table, presenting _its_ different surfaces and reflections of light to different real organisms, he eliminates the one-table-in-its-different-relations in behalf of a multiplicity of totally separate psychical tables! The logic reminds us of the story of the countryman who, after gazing at the giraffe, remarked, "There ain't no such animal." It almost seems, I repeat, as if this self-contradiction in the argument creates in some minds the impression that the object--not the argument--is undergoing the extraordinary reversal of form.
However this may be, the problem indicated in the foregoing cases is simply the good old problem of the many in one, or, less cryptically, the problem of the maintenance of a continuity of process throughout differences. I do not pretend that this situation, though the most familiar thing in life, is wholly without difficulties. But its difficulty is not one of epistemology, that is, of the relation of known to a knower; to take it as such, and then to use it as proof of the psychical nature of a final term, is also to prove that the trail the rocket stick leaves behind is psychical, or that the flower which comes in a continuity of process from a seed is mental.
II Contemporary realists have so frequently and clearly expounded the physical explanation of such cases as have been cited that one is at a loss as to why idealists go on repeating the cases without even alluding to the realistic explanation. One is moved to wonder whether this neglect is just one of those circumstances which persistently dog philosophical discussions, or whether something in the realistic position gives ground (from at least an _ad hominem_ point of view) for the neglect. There is a reason for adopting the latter alternative. Many realists, in offering the type of explanation adduced above, have treated the cases of seen light, doubled imagery, as perception in a way that ascribes to perception an inherent cognitive status. They have treated the perceptions as _cases of knowledge_, instead of as simply natural events having, in themselves (apart from a _use_ that may be made of them), no more knowledge status or worth than, say, a shower or a fever. What I intend to show is that if "perceptions" are regarded as cases of knowledge, the gate is opened to the idealistic interpretation. The physical explanation holds of them as long as they are regarded simply as natural events--a doctrine I shall call naïve realism; it does not hold of them considered as cases of knowledge--the view I call presentative realism.
The idealists attribute to the realists the doctrine that "the perceived object is the real object." Please note the wording; it assumes that there is _the_ real object, something which stands in a contrasting relation with objects not real or else less real. Since it is easily demonstrable that there is a numerical duplicity between the astronomical star and its effect of visible light, between the single finger and the doubled images, the latter evidently, when the former is dubbed "_the_" real object, stands in disparaging contrast to its reality. _If_ it is a case of knowledge, the knowledge refers to the star; and yet not the star, but something more or less unreal (that is, if the star be "the" real object), is known.
Consider how simply the matter stands in what I have called naïve realism. The astronomical star is _a_ real object, but not "the" real object; the visible light is another real object, found, when knowledge supervenes, to be an occurrence standing in a process continuous with the star. Since the seen light is an event within a continuous process, there is no point of view from which its "reality" contrasts with that of the star.
But suppose that the realist accepts the traditionary psychology according to which every event in the way of a perception is also a case of knowing something. Is the way out now so simple? In the case of the doubled fingers or the seen light, the thing known in perception contrasts with the physical source and cause of the knowledge. There _is_ a numerical duplicity. Moreover the thing known by perception is by this hypothesis in relation to a knower, while the physical cause is not. Is not the most plausible account of the difference between the physical cause of the perceptive knowledge and what the latter presents precisely this latter difference--namely, presentation to a knower? If perception is a case of knowing, it must be a case of knowing the star; but since the "real" star is not known in the perception, the knowledge relation must somehow have changed the "object" into a "content." Thus when the realist conceives the perceptual occurrence as an intrinsic case of knowledge or of presentation to a mind or knower, he lets the nose of the idealist camel into the tent. He has then no great cause for surprise when the camel comes in--and devours the tent.
Perhaps it will seem as if in this last paragraph I had gone back on what I said earlier regarding the physical explanation of the difference between the visible light and the astronomical star. On the contrary, my point is that this explanation, though wholly adequate as long as we conceive the perception to be itself simply a natural event, is not at all available when we conceive it to be an attempt at knowing its cause. In the former case, we are dealing with a relation between natural events. In the latter case, we are dealing with the difference between an object as a cause of knowledge and an object as known, and hence in relation to mind. By the "method of difference" the sole explanation of the difference between the two objects is then the absence or presence of relation to a knower.
In the case of the seen light,[60] reference to the velocity of light is quite adequate to account for its time and space differences from the star. But viewed as a case of what is known (on the supposition that perception is knowing), reference to it only increases the contrast between the real object and the object known in perception.
For, being just as much a part of the object that causes the perception as is the star itself, it (the velocity of light) _ought_ logically to be part of what is known in the perception, while it is not. Since the velocity of light is a constituent element in the star, it should be known in the perception; since it is not so known, reference to it only increases the discrepancy between the object of the perception--the seen light--and the real, astronomical star. The same is true of any physical condition that might be referred to: _The very things that, from the standpoint of perception as a natural event, are conditions that account for its happening are, from the standpoint of perception as a case of knowledge, part of the object which, if knowledge is to be valid, ought to be known, but is not._ In this fact we have, perhaps, the ground of the idealist's disregard of the oft-proffered physical explanation of the difference between the perceptual event and _the_ (so-called) real object. And it is quite possible that some realists who read these lines will feel that in my last paragraphs I have been making a covert argument for idealism. Not so, I repeat; they are an argument for a truly naïve realism. The presentative realist, in his appeal to "common-sense" and the "plain man," first sophisticates the umpire and then appeals. He stops a good way short of a genuine naïveté. The plain man, for a surety, does not regard noises heard, lights seen, etc., as mental existences; but neither does he regard them as things _known_. That they are just things is good enough for him. That they are in relation to mind, or in relation to mind as their "knower," no more occurs to him than that they are mental. By this I mean much more than that the formulae of epistemology are foreign to him; I mean that his attitude to these things _as_ things involves their _not_ being in relation to him as a mind or a knower. He is in the attitude of a liker or hater, a doer or an appreciator. When he takes the attitude of a knower he begins to inquire. Once depart from thorough naïveté, and substitute for it the psychological theory that perception is a cognitive presentation to a mind of a causal object, and the first step is taken on the road which ends in an idealistic system.
III For simplicity's sake, I have written as if my main problem were to show how, in the face of a supposed difficulty, a strictly realistic theory of the perceptual event may be maintained. But my interest is primarily in the facts, and in the theory only because of the facts it formulates. The significance of the facts of the case may, perhaps, be indicated by a consideration which has thus far been ignored. In regarding a perception as a case of knowledge, the presentative realist does more than shove into it a relation to mind which then, naturally and inevitably, becomes the explanation of any differences that exist between its subject-matter and some causal object with which it contrasts. In many cases--very important cases, too, in the physical sciences--the contrasting "real object" becomes known by a logical process, by inference--as the contemporary position of the star is determined by calculations from data, not by perception. This, then, is the situation of the presentative realist: If perception is knowledge of its cause, it stands in unfavorable contrast with another indirect mode of knowledge; _its_ object is less valid than the object of inference. I do not adduce these considerations as showing that the case is hopeless for the presentative realist;[61] I am willing to concede he can find a satisfactory way out. But the difficulty exists; and in existing it calls emphatic attention to a case which is certainly and indisputably a case of knowledge--namely, propositions arrived at through inference, judgments as logical assertions.
With relation to the unquestionable case of knowledge, the logical or inferential case, perceptions occupy a unique status, one which readily accounts for their being regarded as cases of knowledge, although in themselves they are natural events. (1) They are the sole ultimate data, the sole media, of inference to all natural objects and processes. While we do not, in any intelligible or verifiable sense, know _them_, we know all things that we do know _with_ or _by_ them.
They furnish the only ultimate evidence of the existence and nature of the objects which we infer, and they are the sole ultimate checks and tests of the inferences. The visible light is a necessary part of the evidence on the basis of which we infer the existence, place, and structure of the astronomical star, and some other perception is the verifying check on the value of the inference. Because of this characteristic use of perceptions, the perceptions themselves acquire, by "second intention," a knowledge status. They _become_ objects of minute, accurate, and experimental scrutiny. Since the body of propositions that forms natural science hangs upon them, _for scientific purposes_ their nature _as_ evidence, _as_ signs, entirely overshadows their natural status, that of being simply natural events.
The scientific man, as scientific, cares for perceptions not in themselves, but as they throw light upon the nature of some object reached by evidence. And since every such inference tries to terminate in a further perception (as its test of validity), the value of inferential knowing depends on perception. (2) Independently of science, daily life uses perceptions as signs of other perceptions.
When a perception of a certain kind frequently recurs and is constantly used as evidence of some other impending perceptual event, the function of habit (a natural function, be it noted, not a psychical or epistemological function) often brings it about that the perception loses its original quality in acquiring a sign-value.
Language is, of course, the typical case. Noises, in themselves mere natural events, through habitual use as signs of other natural events become integrated with what they mean. What they stand for is telescoped, as it were, into what they are. This happens also with other natural events, colors, tastes, etc. Thus, _for practical purposes_, many perceptual events are cases of knowledge; that is, they have been _used_ as such so often that the habit of so using them is established or automatic.
In this brief reference to facts that are perfectly familiar, I have tried to suggest three points of crucial importance for a naïve realism: first, that inferential or evidential knowledge (that involving logical relation) is in the field as an obvious and undisputed case of knowledge; second, that this function, although embodying the logical relation, is itself a natural and specifically detectable process among natural things--it is not a non-natural or epistemological relation; third, that the _use_, practical and scientific, of perceptual events in the evidential or inferential function is such as to make them _become_ objects of inquiry and limits of knowledge, and to such a degree that this acquired characteristic quite overshadows, in many cases, their primary nature.
If we add to what has been said the fact that, like every natural function, the inferential function turns out better in some cases and worse in others, we get a naturalistic or naïvely realistic conception of the "_problem_ of knowledge": Control of the conditions of inference--the only type of knowledge detectable in direct existence--so as to guide it toward better conclusions.
IV I do not flatter myself that I will receive much gratitude from realists for attempting to rescue them from that error of fact which exposes their doctrine to an idealistic interpretation. The superstition, growing up in a false physics and physiology and perpetuated by psychology, that sensations-perceptions are cases of knowledge, is too ingrained. But--_crede experto_--let them try the experiment of conceiving perceptions as pure natural events, not as cases of awareness or apprehension, and they will be surprised to see how little they miss--save the burden of carrying traditionary problems. Meantime, while philosophic argument, such as this, will do little to change the state of belief regarding perceptions, the development of biology and the refinement of physiology will, in due season, do the work.
In concluding my article, I ought to refer, in order to guard against misapprehension, to a reply that the presentative realist might make to my objection. He might say that while the seen light is a case of knowledge or presentative awareness, it is not a case of knowledge of the star, but simply of the seen light, just as it is. In this case the appeal to the physical explanations of the difference of the seen light from its objective source is quite legitimate. At first sight, such a position seems innocent and tenable. Even if innocent, it would, however, be ungrounded, since there is no evidence of the existence of a knower, and of its relation to the seen light. But further consideration will reveal that there is a most fundamental objection. If the notion of perception as a case of adequate knowledge of its own object-matter be accepted, the knowledge relation is absolutely ubiquitous; it is an all-inclusive net. The "ego-centric predicament" is inevitable. This result of making perception a case of knowing will now occupy us.
FOOTNOTES: [58] I am indebted to Dr. Bush's article on "Knowledge and Perception," _Journal of Philosophy, Psychology, and Scientific Methods_, Vol. VI, p. 393, and to Professor Woodbridge's article on "Perception and Epistemology" in the _James Memorial Volume_, as well as to his paper on "Sensations," read at the 1910 meeting of the American Philosophical Association. Since my point of departure and aim are somewhat different, I make this general acknowledgment in lieu of more specific references.
[59] Plato's use of shadows, of reflections in the water, and other "images" or "imitations" to prove the presence in nature of non-being was, considering the state of physical science in his day, a much more sensible conclusion than the modern use of certain images as proof that the object in perception is a psychical content. Hobbes expressly treats all images as physical, as on the same plane as reflections in the water and echoes; the comparison is his.
[60] It is impossible, in this brief treatment, to forestall every misapprehension and objection. Yet to many the use of the term "seen" will appear to be an admission that a case of knowledge is involved.
But is smelling a case of knowledge? Or (if the superstition persists