exists only as a quality, a sense-content, whereas an "idea" exists only as a relation, a reference to reality beyond. "On the one hand," to recall Bradley's antinomy, "no possible idea [as a psychical image] can be that which it means.... On the other hand, no idea [as logical signification] is anything but just what it means."

There is a significant point of agreement between the conceptualist and the empiricist. Both regard imagery as on the level with sense-perception. For the empiricist, as we have seen, the fact that imagery may be compelled to serve as a yoke-fellow of sense-experience const.i.tutes its logical value. For the conceptualist, however, the a.s.sociation of imagery with sense-experience is of no logical consequence whatsoever, save as it may help to intensify the distinction between imagery and meaning. To quote again from Bradley:

For logical purposes the psychological distinction of idea and sensation may be said to be irrelevant, while the distinction of idea and fact is vital. The image, or psychological idea, is for logic nothing but a sensible reality. It is on a level with the mere sensations of the senses. For both are facts and neither are meanings. Neither are cut from a mutilated presentation and fixed as a connection. Neither are indifferent to their place in the stream of psychical events, their time and their relations to the presented congeries. Neither are adjectives to be referred from their existence, to live on strange soils, under other skies, and through changing seasons. The lives of both are so entangled with their environment, so one with their setting of sensuous particulars, that their character is destroyed if but one thread is broken.[86]

This point of agreement between conceptualism and empiricism, this placing of imagery and sense-experience on a common level, serves to bring into relief fundamental differences between the two schools of thought; fundamental, because they have to do with the nature of reality itself. The conceptualist in his zealous endeavor to distinguish between imagery and logical meaning has come perilously near driving imagery into the arms of reality. It is the opportunity of empiricism to make them one. How can conceptualism prevent the union? Has it not disarmed itself? The act of judgment, which includes within itself logical meaning as predicate, refers to a reality beyond the act. Both imagery and reality, then, lie outside of the act of judgment! What alliance, or _mesalliance_, may they not form, one with the other?

The difficulties we have noted thus far in the discussion are due to a large extent, I believe, to incomplete psychological a.n.a.lysis of logical machinery. The empiricist has not carried the psychology of logic as far as the conceptualist, although the latter might be the loudest to disclaim the honor. I will not try to prove this statement, but simply give it as a reason why, in the interest of brevity, I shall pa.s.s with little comment over the psychological shortcomings and contributions of empirical logic, and devote what s.p.a.ce remains to the psychology implicitly worked out by conceptual logic, and to its possible development, with special reference, of course, to the problem of the logical function of imagery.

The logical distinction, which practically amounts to a separation between imagery and meaning, is the counterpart of the psychological distinction between stimulus and response, between the two poles of sensori-motor activity, where the stimulus is defined in consciousness in the form of imagery, in the form of sense-qualities centrally excited, and where the response is directed and controlled _via_ this imagery, so as to function in bringing some end, project, purpose, or ideal, nearer to realization, some problem nearer to solution.

Psychologically, there is no break between image and response, between thought and action. The stimulus is a condition of action, in both senses of the ambiguity of the word "condition." (1) It _is_ action; it is a state or condition of action. (2) It is also an initiation of action. _If_ the appropriate stimulus, then the desired action. The response to an image is the meaning of the image. Or, the response to any stimulus _via_ an image--mediated, controlled or directed by an image--is the meaning of that image. The less imagery involved in any response, the greater the presumption in favor of the belief that the response is either an instinctive impulse or else has become a habit of mind, an adequate idea. The reduction and loss of sense-content which an image may undergo--the wearing away of an image, it is sometimes called--is not a sign that this sense-content has no logical function; but rather that it has fulfilled a logical function so well that it has made part of itself useless. The husk, to recall one of Mr. Bradley's comparisons, that useless husk, tends to fall away, to lapse from consciousness, after it has served the purpose of helping to bring the kernel of truth to fruition.

This raises again the original question as to whether the sense-content, the quality, the existential quality, of an image has a logical function. I will ask first whether it has a function from the standpoint of psychology. We will agree with the empiricist that the content of an image is representative, that it is a return, a revival, of a sense-content previously experienced through the activity of sense-organs stimulated from the periphery. What is the function, then, of the representative image? Sensation, quality, as we have implied above, is the stimulus come to consciousness. To explain how a stimulus can "come" to consciousness is a problem I will not attempt to go into here. I a.s.sume as a fact that there are times when we know what we are about; when we are conscious of the stimuli, or conditions of action, which are tending in this direction or in that, and when through this consciousness we exercise a controlling influence over action by selecting and reinforcing certain stimuli and suppressing or inhibiting others. It is true that we do not always realize to how great an extent our actions are controlled by stimuli which do not come to consciousness, by reflexes, instincts, and habits which do not rise above the threshold of imagery. And when this vast complex of hidden machinery is partly revealed to us, it may either cause the beholder to take a materialistic, mechanical, or fatalistic view of existence, to say that we are the victims of our own machinery, or else it may induce the other extreme of more or less mystic p.r.o.nouncements regarding the province of the subconscious, of the subliminal self; thus out of partial views, out of half-truths, metaphysical problems arise and arm for mutual conflict. Nevertheless, there is a presumption, amounting in most minds to a conviction, that we do at times consciously control some of our actions. And it is only making this conviction a little more explicit to say that we consciously control our actions through becoming aware of the stimuli, or conditions of action, and through selecting and reinforcing them.

Is it begging the question to speak of consciousness as exercising a selective function with reference to stimuli? From the standpoint of psychology, I cannot see that it is. No characteristic of consciousness has been more clearly made out, both reflectively and experimentally, than its selective function, than its ability to pick out and intensify within certain limits the stimuli or conditions of action.

The representational image is a stimulus come to consciousness in the same way that a sensation is a stimulus come to consciousness. It is both a direct and an indirect stimulus. The terms "direct" and "indirect" are used as relative solely to the demands of the particular situation out of which they arise. By direct stimulus I mean a stimulus which initiates with almost no appreciable delay the response or att.i.tude appropriate to the demands of a given situation, bridging the difficulties, removing the obstacles, or solving the problem with the minimum of conscious reflection. As an image becomes more and more of a working symbol, an idea, it tends to become simply a direct stimulus.

By an "indirect stimulus" is meant a stimulus initiating a response which, if not inhibited, would be irrelevant to the situation, yet which may represent stimuli which are not found in the immediate field of sense-perception, and which are essential to the carrying on of the activity. The situation is a problematic one. Acquired habits or mental adjustments break down at some point or fail to operate smoothly, either owing to the absence of customary stimuli or to the presence of new and untried conditions of action. Part of the stress of meeting such a situation as this falls on the side of discovering appropriate stimuli and part on the side of developing out of habits already acquired new methods of response.

In such a situation as this, imagery may function on the side of _stimulus_ when, taking its cue from the stimuli which are actually present, and which grow out of the strain and friction, it represents the missing conditions of action sufficiently to direct a search for them. It projects a map, so to speak, in which the fragmentary conditions immediately present to sense-perception may find their bearings, or in which in some way the missing members may be discovered.

A familiar instance of this would be the experience one sometimes has in trying to recall the forgotten name of an acquaintance. The images of scenes a.s.sociated with the acquaintance, of various letters and sounds of words a.s.sociated with his name, which may be called to mind, do not function so much as direct stimuli as they do as intermediate or indirect stimuli. It is a case of casting about for the image that will function as a direct stimulus in bringing an acquired but temporarily lost adjustment into play.

Image functions on the side of _response_, on the side of developing new habits, new forms of adjustment, in so far as the conditions of action which it represents, or projects, are not the actual conditions of action, either because they are so inaccessible as to demand development of new habits for purposes of attaining them, or else because, though actually present, they stimulate relatively uncontrolled aesthetic or emotional responses, whose very expression, however, may be translated into a demand for more adequate, intelligent, controlled habits or adjustments. The conscious projection of the unattained, even of the unattainable, not only marks a certain degree of attainment, but is the initiation of further development. Here we see again that a stimulus is a condition of action in both senses of the ambiguity of the word "condition." It is both a state or condition of activity, and an initiation or condition of further activity.

As an indirect stimulus growing out of a problematic situation imagery necessarily brings in more or less irrelevant material. If I may be permitted the paradox, imagery would not be relevant if it did not bring in the irrelevant. The novelty of the situation makes it impossible to say in advance what will be relevant. Hence the demand for range and play of imagery. It is only the successful adjustment finally hit upon and worked out that is the test of the relevancy of the imagery which antic.i.p.ated it. Even this test may be unfair, since it is likely to discount the value of imagery which is now ruled out, but which may have been indispensable in turning up the proper cues in the course of the process of reflection and experiment.

To restate the point in regard to the psychological function of imagery.

Imagery functions in representing control as ideal, not as fact. It represents a possible process of reconstructing adjustments and habits; it is not an actual and complete readjustment. It arises normally in a stress, in the presence of fresh demands and new problems. It looks forward in every possible direction, because it is important and difficult to foresee consequences. But suppose the new adjustment to be made with reasonable success--reasonable, note. Suppose the ideal to be realized. With practice the adjustment becomes less problematic, more under control--that is, it comes to require less conscious attention to bring it about. The image loses some of its sensuous content. It becomes worn away, more remote, until at last it becomes respectably vague and abstract enough to be cla.s.sed as a concept. Imagery is the stimulus of the reconstructive process between habit and habit, concept and concept, idea and idea.

We now return to the original question regarding the logical function of imagery. There is only one condition, I believe, on which we can accept the a.s.sumption of both empiricist and conceptualist that imagery is on the same level with sense-perception, and that is the a.s.sumption that meaning, logical meaning, is on the same level with habit, habit naming the more obvious, overt forms of response to stimuli, logical meaning naming the more internal forms of response or reference. Psychical response and logical reference thus become equivalent terms.

We have seen that imagery may exercise two functions with reference to habit, as direct and as indirect stimulus; so also with reference to logical meaning, imagery may be the stimulus to a direct reference of the idea to reality, or it may present, or mirror, conditions with regard to which some new meaning is to be worked out. The quality, the sense-content, of imagery may _per se_ suffice directly to arouse a habitual att.i.tude, to call forth an immediate reference to reality. It may cause one to "tumble" to what is taking place, to "catch on," to apprehend (pardon these expressions for the sake of their description of the motor aspect of meaning), as when we say, for example: "It came over me like a flash what I was to do, and I did it." Our more abstract and complicated forms of judgment and reasoning, in which the imagery involved is reduced to the minimum of conscious, qualitative content, are of the same order, though at the other extreme, so far as immediate overt expression is concerned. We are working along lines of habitual activity so familiar that we can work almost in the dark. We need no elaborate imagery. Guided only by the waving of a signal flag or by the shifting gleam of a semaph.o.r.e, we thread our way swiftly through the maze of tracks worn smooth by use and habit. But suppose a new line of habit is to be constructed. No signal flags or semaph.o.r.es will suffice.

A detailed survey of the proposed route must be had, and here is where imagery with a rich and varied yet flexible sensuous content, growing out of previous surveys, may function in projecting and antic.i.p.ating the new set of conditions, and thus become the stimulus of a new line of habit, of a new and more far-reaching meaning. As this new line of habit, of meaning, gets into working order with the rest of the system, imagery tends normally to decline again to the role of signal flags and semaph.o.r.es.

The distinction in logical theory between "image" and "idea" which we have been considering is only a half-truth from the point of view of psychology. It virtually limits the "idea" to a fixed, unalterable reference of a fragment of a desiccated image to a reality beyond. It indifferently loses the play and richness of imagery to the floating remnants of sense-content, or to an external reality. It limits itself to an examination of a final stage in thinking, a stage in which the image acts as a direct stimulus, a stage in which the sense-content of the image has little or no function _per se_, because this content now initiates directly a habitual adjustment, a worked-out and established adaptation of means to end. It overlooks the process of conscious reflection which logically precedes every such adjustment not purely instinctive or accidental, a process in which imagery as representational functions indirectly in bringing the resources of past experience, the fund of acquired habits, to bear upon the fragmentary and problematic elements of sense-experience actually present, thus maintaining the flow and continuity of experience. It fails to recognize that in the inseparable a.s.sociation of meaning with quality, of "idea"

with "image," there goes the possibility of working out and applying new meanings from old, of developing deeper meanings, of testing and affirming more inclusive and universal meaning.

We are confronted with this alternative. Either the image has a logical function in virtue of its sense-content, or else the image functions logically merely as a symbol, the sense-content of which is a matter of complete logical indifference. According to the empiricist, the former is the case, according to the conceptualist, the latter. The empiricist would say that he needs the image to piece out the data upon which logical processes operate. Having met this need, the image is retired from active service. For the empiricist the processes of thought, observing, comparing, generalizing, etc., are as independent of the data they use as, for the conceptualist, logical meaning, reference, and "idea" are independent of the sense-content of the "image." In reality he agrees with the conceptualist in excluding the sense-content of the image from the processes of thought, and hence from the domain of logic.

From the standpoint of psychological theory the conceptualist is an improvement over the empiricist. He has gone a step farther in the a.n.a.lysis of thought-processes by showing that they are bound up with some kind of imagery, however irrelevant, inconsequential, and worn down the sense-quality of that imagery may be. His statement of ideas as references to reality lends itself readily, as we have seen, to the unitary conception in psychology of ideo-motor, or sensori-motor, activity. But is this where logical theory is to stop, while psychology as a study of "states of consciousness" takes up the unfinished tale and carries it forward? It seems hardly possible, unless logic is willing to give over its task of thinking about thinking.

Reduce the image to a mere symbol. Let its sense-quality be a matter of complete indifference. What have you, then, but an elementary and primitive type of reflex action? It is of no particular consequence even from what sense-organ it appears to proceed, or whether it appears to be peripherally or centrally excited. It is simply a case of feel and act; touch and go. Is this thinking? It may be regarded as either the germ or the finality of thinking, but what most of us are inclined to believe is the true subject-matter of logic is not to be limited to a simple reflex, or even to a chain of reflexes. It is something more complex, even if nothing more than an intricate tangle of chains of reflexes.

The complexity of the process called thinking does not reside alone in the instinctive or habitual reflexes involved. The more instinctive and habitual any adjustment may be, the less is it a matter of thought, as everyone knows, although its biological complexity is none the less patent to one who looks at it from the outside. The complexity of the thinking process resides in consciousness also; it resides in the imagery, the stimuli, the mere symbols, if you like, that have "come" to consciousness. As soon as the complexity begins to be _felt_, as soon as any discrimination whatsoever begins to be introduced or appreciated, at that instant the sense-content, the quale, of imagery begins to have a logical function. Conscious discrimination, however vague and evanescent, and the logical function of the quale of imagery are born together, unless one chooses to regard the more obvious and deliberate forms of conscious discrimination as more characteristic of a logical process. It is only as the sense-contents of various images are discriminated and compared that anything like thinking can be conceived to go on. The particular sense-content of an image, instead of being a matter of logical indifference, is the condition, the possibility, of thinking.

The conceptualist has contributed to the data of descriptive psychology by calling attention, by implication at least, to the remote and reduced character of the imagery which may characterize thinking. But it by no means follows that the more remote and reduced the sense-content of an image becomes, the less important is that sense-content for thinking, the less demand for discrimination. On the contrary, the sense-content that remains may be of supreme logical importance. It may be the quintessence of meaning. It may be the conscious factor which, when discriminated from another almost equally sublimated conscious factor, may determine a whole course of action. The delicacy and rapidity with which these reduced forms of imagery as they hover about the margin of consciousness or flit across its focus are discriminated and caught, are points in the technique of that long art of thinking, begun in early childhood. The fact that questionnaire investigations--like that of Galton's, for example--have in many instances failed to discover in the minds of scientists and advanced thinkers a rich and varied furniture of imagery does not argue the poverty of imagery in such minds; it argues, rather, a highly developed technique, a species of virtuosity, with reference to the sense-content of the types of imagery actually in use.

To push a step farther the alternative we have already stated in a preliminary way: Either the "idea," or "logical meaning," lies outside of the process of thinking, as a mere impulse or reflex; or else, in virtue of the sense-content of its "image," it enters into that conscious process of discrimination, comparison, and selection, of light and shade, of doubt and inquiry, which const.i.tutes the evolution of a judgment, which makes the life-history of a movement of thought.

IX

THE LOGIC OF THE PRE-SOCRATIC PHILOSOPHY[87]

It is not the purpose of this study to show that the Pre-Socratics possessed a system of logic which is now for the first time brought to the notice of the modern world. Indeed, there is nothing to indicate that they had reflected on mental processes in such a way as to call for an organized body of canons regulating the forms of concepts and conclusions. Aristotle attributed the discovery of the art of dialectic to Zeno the Eleatic, and we shall see in the sequel that there was much to justify the opinion. But logic, in the technical sense, is inconceivable without concepts, and from the days of Aristotle it has been universally believed that proper definitions owe their origin to Socrates. A few crude attempts at definition, if such they may be rightly called, are referred to Empedocles and Democritus. But in so far as they were conceived in the spirit of science, they essayed to define things materially by giving, so to speak, the chemical formula for their production. Significant as this very fact is, it shows that even the rudiments of the canons of thought were not the subjects of reflection.

In his _Organon_ Aristotle makes it evident that the demand for a regulative art of scientific discourse was created by the eristic logic-chopping of those who were most deeply influenced by the Eleatic philosophy. Indeed, the case is quite parallel to the rise of the art of rhetoric. Aristotle regarded Empedocles as the originator of that art, as he referred the beginnings of dialectic to Zeno. But the formulation of both arts in well-rounded systems came much later. As men conducted lawsuits before the days of Tisias and Corax, so also were the essential principles of logic operative and effective in practice before Aristotle gave them their abstract formulation.

While it is true, therefore, that the Pre-Socratics had no formal logic, it is equally true, and far more significant, that they either received from their predecessors or themselves developed the conceptions and the presuppositions on which the Aristotelian logic is founded. One of the objects of this study is to inst.i.tute a search for some of these basic conceptions of Greek thought, almost all of which existed before the days of Socrates, and to consider their origin as well as their logical significance. The other aim here kept in view is to trace the course of thought in which the logical principles, latent in all attempts to construct and verify theories, came into play.

It is impossible, no doubt, to discover a body of thought which does not ground itself upon presuppositions. They are the warp into which the woof of the system, itself too often consisting of frayed ends of other fabrics, is woven with the delight of a supposed creator. Rarely is the thinker so conscious of his own mental processes that he is aware of what he takes for granted. Ordinarily this retirement to an interior line takes place only when one has been driven back from the advanced position which could no longer be maintained. Emerson has somewhere said: "The foregoing generations beheld G.o.d and Nature face to face; we through their eyes. Why should not we also enjoy an original relation to the universe? Why should not we have a poetry and philosophy of insight and not of tradition, and a religion by revelation to us and not the history of theirs?" The difficulty lies precisely in our faith in immediate insight and revelation, which are themselves only short-cuts of induction, psychological short circuits, conducted by media we have disregarded. Only a fundamentally critical philosophy pushes its doubt to the limit of demanding the credentials of those conceptions which have come to be regarded as axiomatic.

The need of going back of Aristotle in our quest for the truth is well shown by his att.i.tude toward the first principles of the several sciences. To him they are immediately given--[Greek: amesoi protaseis]--and hence are ultimate _a priori_. The historical significance of this fact is already apparent. It means that in his day these first principles, which sum up the outcome of previous inductive movements of thought, were regarded as so conclusively established that the steps by which they had been inferred were allowed to lapse from memory.

No account of the history of thought can hope to satisfy the demands of reason that does not _explain_ the origin of the convictions thus embodied in principles. The only acceptable explanation would be in terms of will and interest. To give such an account would, however, require the knowledge of secular pursuits and ambitions no longer obtainable. It might be fruitful of results if we could discover even the theoretical interests of the age before Thales; but we know that in modern times the direction of interest characteristic of the purely practical pursuits manifests its reformative influences in speculation a century or more after it has begun to shape the course of common life.

Hence we might misinterpret the historical data if they were obtainable.

But general considerations, which we need not now rehea.r.s.e, as well as indications contained in the later history of thought, hereinafter sketched, point to the primacy of the practical as yielding the direction of interest that determines the course it shall take.

It was said above that the principles of science are the result of an inductive movement, and that the inductive movement is directed by an interest. Hence the principles are contained in, or rather are the express definition of, the interest that gave them birth. In other words, there is implied in all induction a process of deduction. Every stream of thought embraces not only the main current, but also an eddy, which here and there re-enters it. And this is one way of explaining the phenomenon which has long engaged the thought of philosophers, namely, the fact of successful antic.i.p.ations of the discoveries of science or, more generally still, the possibility of synthetic judgments _a priori_.

The solution of the problem is ultimately contained in its statement.[88]

To arrive at a stage of mentality not based on a.s.sumptions one would have, no doubt, to go back to its beginnings. Greek thought, even in the time of Thales, was well furnished with them. We cannot pause to catalogue them, but it may further our project if we consider a few of the more important. The precondition of thought as of life is that nature be uniform, or ultimately that the world be rational. This is not even, as it becomes later, a conscious demand; it is the primary ethical postulate which expresses itself in the confidence that it is so. Viewed from a certain angle it may be called the principle of sufficient reason. Closely a.s.sociated with it is the universal belief of the early philosophers of Greece that everything that comes into being is bound up inseparably with that which has been before; more precisely, that there is no absolute, but only relative, Becoming. Corollaries of this axiom soon appeared in the postulates of the conservation of matter or ma.s.s, and the conservation of energy, or more properly for the ancients, of motion. Logically these principles appear to signify that the subject, while under definition, shall remain just what it is; and that, in the system const.i.tuted of subject, predicate, and copula, the terms shall "stay put" while the adjustment of verification is in progress. It is a matter of course that the constants in the great problem should become permanent landmarks.

Other corollaries derive from this same principle of uniformity. Seeing that all that comes to be in some sense already is, there appears the postulate of the unity of the world; and this unity manifests itself not only in the integrity and h.o.m.ogeneity of the world-ground, but also in the more ideal conception of a universal law to which all special modes of procedure in nature are ancillary. In these we recognize the insistent demand for the organization of predicate and copula. Side by side with these formulae stands the other, which requires an ordered process of becoming and a graduated scale of existences, such as can mediate between the extremes of polarity. Such series meet us on every hand in early Greek thought. The process of rarefaction and condensation in Anaximenes, the [Greek: hodos ano kato] of Herac.l.i.tus, the regular succession of the four Empedoclean elements in almost all later systems--these and other examples spontaneously occur to the mind. The significance of this conception, as the representative of an effective copula, will presently be seen. More subtle, perhaps, than any of these principles, though not allowed to go so long unchallenged, is the a.s.sumption of a [Greek: physis], that is, the a.s.sumption that all nature is instinct with life. The logical interpretation of this postulate would seem to be that the concrete system of things--subject, predicate, copula--const.i.tutes a totality complete in itself and needing no jog from without.

In this survey of the preconceptions of the early Greek philosophers I have employed the terms of the judgment without apology. The justification for this course must come ultimately, as for any a.s.sumption, from the success of its application to the facts. But if "logic" merely formulates in a schematic way that which in life is the manipulation of concrete experience, with a view to attaining practical ends, then its forms must apply here as well as anywhere. Logical terminology may therefore be a.s.sumed to be welcome to this field where judgments are formed, induction is made from certain facts to defined conceptions, and deductions are derived from principles or premises a.s.sumed. Speaking then in these terms we may say that the Pre-Socratics had three logical problems set for them: First, there was a demand for a predicate, or, in other words, for a theory of the world. Secondly, there was the need of ascertaining just what should be regarded as the subject, or, otherwise stated, just what it was that required explanation. Thirdly, there arose the necessity of discovering ways and means by which the theory could be predicated of the world and by which, in turn, the hypothesis erected could be made to account for the concrete experience of life: in terms of logic this problem is that of maintaining an efficient copula. It is not a.s.sumed that the sequence thus stated was historically observed without crossing and overlapping; but a survey of the history of the period will show that, in a general way, the logical requirements a.s.serted themselves in this order.

1. Greek philosophy began its career with induction. We have already stated that the preconceptions with which it approached its task were the result of previous inductions, and indeed the epic and theogonic poetry of the Greeks abounds in thoughts indicative of the consciousness of all of these problems. Thus Homer is familiar with the notion that all things proceed from water,[89] and that, when the human body decays, it resolves itself into earth and water.[90] Other opinions might be enumerated, but they would add nothing to the purpose. When men began, in the spirit of philosophy, to theorize about the world, they a.s.sumed that it--the subject--was sufficiently known. Its existence was taken for granted, and that which engaged their attention was the problem of its meaning. What predicate--so we may formulate their question--should be given to the subject? It is noticeable that their induction was quite perfunctory. But such is always the case until there are rival theories competing for acceptance, and even then the impulse to gather up evidence derived from a wide field and a.s.sured by resort to experiment comes rather with the desire to test a hypothesis than to form it. It is the effort to _verify_ that brings out details and also the negative instances. Hence we are not to blame Thales for rashness in making his generalization that all is Water. We do not know what indications led to this conclusion. Aristotle ventured a guess, but the motives a.s.sumed for Thales agree too well with those which weighed with Hippo to admit of ready acceptance.

Anaximander, feeling the need of deduction as a sequel to induction, found his predicate in the Infinite. We cannot now delay to inquire just what he meant by the term; but it is not unlikely that its very vagueness recommended it to a man of genius who caught enthusiastically at the skirts of knowledge. Anaximenes, having pushed verification somewhat farther and eliciting some negative instances, rejected water and the Infinite and inferred that all was air. His [Greek: arche] must have the quality of infinity, but, a copula having been found in the process of rarefaction and condensation, it must occupy a determinate place in the series of typical forms of existence. The logical significance of this thought will engage our attention later.

Meanwhile it may be well to note that thus far only _one_ predicate has been offered by each philosopher. This is doubtless due to the preconception of the unity and h.o.m.ogeneity of the world, of which we have already made mention. Although at the beginning its significance was little realized, the conception was destined to play a prominent part in Greek thought. It may be regarded from different points of view not necessarily antagonistic. One may say, as indeed has oftentimes been said, that it was due to ignorance. Men did not know the complexity of the world, and hence declared its substance to be simple. Again, it may be affirmed that the a.s.sumption was merely the nave reflex of the ethical postulate that we shall unify our experience and organize it for the realization of our ideals. While increased knowledge has multiplied the so-called chemical elements, physics knows nothing of their differences, and chemistry itself demands their reduction.

The extension and enlarged scope of h.o.m.ogeneity came in two ways: First, it presented itself by way of abstraction from the particular predicates that may be given to things. This was due to the operation of the fundamental a.s.sumption that the world must be intelligible. Thus, even in Anaximander, the world-ground takes no account of the diversity of things except in the negative way of providing that the contrariety of experience shall arise from it. We are therefore referred for our predicate to a somewhat behind concrete experience. The Pythagoreans fix upon a single aspect of things as the essential, and find the meaning of the world in mathematical relations. The Eleatics press the conception of h.o.m.ogeneity until it is reduced to ident.i.ty. Ident.i.ty means the absence of difference; hence, spatially considered, it requires the negation of a void and the indivisibility of the world; viewed temporally, it precludes the succession of different states and hence the possibility of change.

We thus reach the acute stage of the problem of the One and the Many.

The One is here the predicate, the subject is the Many. The solution of the difficulty is the task of the copula, and we shall recur to the theme in due time. It may be well, however, at this point to draw attention to the fact that the One is not always identical with the predicate, nor the Many with the subject. In the rhythmic movement of erecting and verifying hypotheses the interest shifts and what was but now the predicate, by taking the place of the premises, comes to be regarded as the given from which the particular is to be derived or deduced. There is thus likewise a shift in the positions of existence and meaning. The subject, or the world, was first a.s.sumed as the given means with which to construct the predicate, its meaning; once the hypothesis has been erected, the direction of interest shifts back to the beginning, and in the process of verification or deduction the quondam predicate, now the premises, becomes the given, and the task set for thought is the derivation of fact. For the moment, or until the return to the world is accomplished, the One is the only real, the Manifold remains mere appearance.

The second form in which the sense of the h.o.m.ogeneity of the world embodies itself is not, like the first, static, but is altogether dynamic. That which makes the whole world kin is neither the presence nor the absence of a quality, but a principle. The law thus revealed is, therefore, not a matter of the predicate, but is the copula itself.

Hence we must defer a fuller consideration of it for the present.

2. As has already been said, the inductive movement implies the deductive, and not only as something preceding or accompanying it, but as its inner meaning and ultimate purpose. So too it was with the earliest Greek thinkers. Their object in setting up a predicate was the derivation of the subject from it. In other words their ambition was to discover the [Greek: arche] from which the genesis of the world proceeds. But deduction is really a much more serious task than would at first appear to one who is familiar with the Aristotelian machinery of premises and middle terms. The business of deduction is to reveal the subject, and ordinarily the subject quite vanishes from view. Induction is rapid, but deduction lags far behind. It may require but a momentary flash of "insight" on the part of the physical philosopher to discover a principle; if it is really significant, inventors will be engaged for centuries in deducing from it applications to the needs of life by means of contrivances. Thus after ages we come to know more of the subject, which is thereby enriched. The contrivances are the representatives of the copula in practical affairs; in quasi-theoretical spheres they are the apparatus for experimentation. It has just been remarked that by the application of the principles to life it is enriched; in other words, it receives new meaning, and new meaning signifies a new predicate. Theory is at times painfully aware of the mult.i.tude of new predicates proposed; rarely does it realize that there has been created a new heaven and a new earth. Without the latter, the former would be absurd.

Men take very much for granted and regard almost every achievement as a matter of course. Hence they do not become aware of their changed position except as it reflects itself in new schemes and in a larger outlook. The subject receives only a summary glance to discover what new predicate shall be evolved. Hence, while there is in Greek philosophy a strongly marked deductive movement, the theoretical results to the subject are insignificant. Thales seems, indeed, to have had no means to offer for the derivation of the world, but he evidently had no doubt that it was possible. With him and with others the a.s.sumption, however vaguely understood, seems to have been that the subject, like the predicate, was simple. Thus the essential unity of the world, considered as existence no less than as meaning, is a foregone conclusion. The sense of a division in the subject seems to arise with Empedocles when, reaping the harvest of the Eleatic definition of substance, he parted the world, as subject and as predicate, into four elements.