The Principles of Psychology, Vols. 1-2

* Cf . A. de Morgan : Syllabus of a proposed System of Logic (1860), pp. Nothing but the clear sight of the ideas themselves shows whether the axiom of skipped intermediaries applies to them or not. Their connections, immediate and remote, flow from their inward natures. We try to consider them in certain ways, to bring them into certain relations, and we find that sometimes we can and sometimes we cannot The question whether there are or are not inward and essential connections between conceived objects as such, really is the same thing as the question whether we can get any new perception from mentally coupling them together , or pass from one to another by a mental operation which gives a result. In the case of some ideas and operations we get a result ; but no result in the case of others. Where a result comes, it is due exclusively to the nature of the ideas and of the operation. Take blueness and yellowness, for example. We can operate on them in some ways, but not in other ways. We can compare them ; but we cannot add one to or subtract it from the other. We can refer them to a common kind, color ; but we cannot make one a kind of the other, or infer one from the other. This has nothing to do with experience. For we can add blue pigment to yellow pigment, and sub^ tract it again, and get a result both times. Only we know perfectly that this is no addition or subtraction of the blue and yellow qualities or natures themselves.*

There is thus no denying the fact that the mind is filled idth necessary and eternal relatione tvhich it finds betiveen certain of its ideal conceptions, and, luhich form a determinate system, independent of the order offrequenxiy in which experience may have associated the conxicption' s originals in time and space. Shall we continue to call these sciences ' intuitive,' ' innate,' or * a priori ' bodies of truth, or not ?t Personally f Some readers may expect me to plunge into the old debate as to whether the a priori truths are ' analytic ' or • synthetic' It seems to me that the distinction is one of Kant's most unhappy legacies, for the reason that it is impossible to make it sharp. No one will say that such analytic judgments as "equidistant lines can nowhere meet " are pure tautologies. The predicate is a somewhat new way of conceiving as well as of naming the subject. There is something ' ampliative ' in our greatest truisms, our state of mind is richer after than before we have uttered them. This

I should like to do so. But I hesitate to use the terais» on account of the odium which controversial history haa made the whole of their connotation for many worthy persons. The most politic way not to alienate these readers is to flourish the name of the immortal Locke. For in trutk I have done nothing more in the previous pages than to make a little more explicit the teachings of Locke's fourtk book : "The immutability of the same relations between the same immutable things is now the idea that shows him that if the three angles of a triangle were once equal to two right angles, they will always be equal to two right ones. And hence he comes to be certain that what was once true in the case is always true ; what ideas once agreed will always agree . . . Upon this ground it is that particular demonstrations in mathematics afford general knowledge. If, then, the perception that the same ideas will eternally have the same habitudes and relations be not a sufficient ground of knowledge, there could be no knowledge of general propositions in mathematics. ... All general knowledge lies only in our own thoughts, and consists barely in the contemplation of our abstract ideas. Wherever we perceive any agreement or disagreement amongst them, there we have general knowledge ; and by putting the names of those ideas together accordingly in propositions, can with certainty pronounce general truths. . . . What is once known of such ideas will be perpetually and forever true. So that, as to all general knowledge, we must search and find it only in our own minds and it is only the examining of our own ideas that furnisheth us with that. Truths belonging to essences of things (that is, to abstract ideas) are

being the case, the question "at what point does the new state of mind cesi&e to he implicit in the old?" is too vague to be answered. The only sharp way of defining synthetic propositions would be to say that they express a relation between two data at least. But it is hard to find any proposition which cannot be construed as doing this. Even verbal definitions do it. Such painstaking attempts as that latest one by Mr. D. G. Thompson to prove all necessary judgments to be analytic (System of Psychology, II. pp. 232 ff.) seem accordingly but nugce difficiles, and little better than wastes of ink and paper. All philosophic interest vanishes from the question, the moment one ceases to ascribe to any a priori truths (whether analytic or synthetic) that " legislative character for all possible experience " which Kant believed in. We ourselves have denied such legislative character, and contended that it was for experience itself to prove whether its data can or cannot be assimilated to those ideal terms i)etween which a j9rw?n relations obtain. The analyticsynthetic debate is thus for us devoid of all significance. On the whole, the best recent treatment of the question known to me is in one of A. Spir's works, his Denkeii und Wirklichkeit, I think, but 1 cannot now find the page.

'i^einal, and are to be found out only by the contemplation of those wsences. . . . Knowledge is the consequence of the ideas (be they what they will) that are in our minds, producing there certain general propositions. . . . Such propositions are therefore called 'eternal truths,' . . because, being once made about abstract ideas so as to be true, they will, whenever they can be supposed to be made again, at anytime past ur to come, by a mind having those ideas, always actually be true. For names being supposed to stand perpetually for the same ideas, and the same ideas having immutably the same habitudes one to another, propositions concerning any abstract ideas that are once true must needs be eternal verities."

But what are these eternal verities, these * agreements,' which the mind discovers by barely considering its own fixed meanings, except what I have said ? — relations of likeness and difference, immediate or mediate, between the terms of certain series. Classification is serial comparison, logic mediate subsumption, arithmetic mediate equality of different bundles of attentionstrokes, geometry mediate equality of different ways of carving space. None of these eternal verities has anything to say about facts, about what is or is not in the world. Logic does not say whether Socrates, men, mortals or immortals exist; arithmetic does not tell us where her 7's, 5's, and 12's are to be found; geometry affirms not that circles and rectangles are real. All that these sciences make us sure of is, that if these things are anywhere to be found, the eternal verities will obtain of them. Locke accordingly never tires of telling us that the

*' universal propositions of whose truth or falsehood we can have certain knowledge, concern not existence. . . . These universal and selfevident principles, being only our constant, clear, and distinct knowledge of our own ideas more general or comprehensive, can assure us of nothing that passes without the mind; their certainty is founded only upon the knowledge of each idea by itself, and of its distinction from others ; about which we cannot be mistaken whilst they are in our minds. . . , The mathematician considers the truth and properties belonging to a rectangle or circle only as they are in idea in his own mind. For it is possible he never found either of them existing mathematically, i.e., precisely true, in his life. But yet the knowledge he has of any truths or properties belonging to a circle, or any other mathematical figure, are nevertheless true and certain even of real things existing; because real things are no farther concerned nor intended to be meant by any such propositions, than as things really agree to those archetypes in his mind. Is it true of the idea of a triangle, that iti

three angles are equal to two right ones ? It is true also of a triangle wherever it really exists. Whatever other figure exists that is not exactly answerable to that idea in his mind is not at all concerned in that proposition. And therefore he is certain all his knowledge concerning such ideas is real knowledge: because, intending things no farther than they agree with those his ideas, he is sure what he knows concerning those figures when they have barely an ideal existence in his mind will hold true of them also when they have a real existence in matter." But "that any or what bodies do exist, that we are left to our senses to discover to us as far as they can." *

Locke accordingly distinguishes betv^^een ' mental truth * and * real truth.' t The former is intuitively certain ; the latter dependent on experience. Only hypothetically can we affirm intuitive truths of real things — by supposing, namely, that real things exist which correspond exactly with the ideal subjects of the intuitive propositions. If our senses corroborate the supposition all goes well. But note the strange descent in Locke's hands of the dignity of a priori propositions. By the ancients they were considered, without farther question, to reveal the constitution of Reality. Archetypal things existed, it was assumed, in the relations in which we had to think them. The mind'a necessities were a warrant for those of Being ; and it was not till Descartes' time that scepticism had so advanced (in * dogmatic ' circles) that the warrant must itself be warranted, and the veracity of the Deity invoked as a reason for holding fast to our natural beliefs.

But the intuitive propositions of Locke leave us as regards outer reality none the better for their possession. We still have to "go to our senses*' to find what the reality is. The vindication of the intuitionist position is thus a barren victory. The eternal verities which the very structure of our mind lays hold of do not necessarily themselves lay hold on extra-mental being, nor have they, as Kant pretended later,| a legislating character even

X Kant, by the way, made a strange tactical blunder in his way of showing that the forms of our necessary thought are underived from experience. He insisted on thought-forms with which experience largely agrees, forgetting that the only forms which could not by any possibility for all possible experience. They are primarily interesting only as subjective facts. They stand waiting in the mind, forming a beautiful ideal network ; and the most we can say is that we hope to discover outer realities over which the network may be flung so that ideal and real may coincide.

And this brings us back to ' science * from which we diverted our attention so long ago (see p. 640). Science think>3 that she has discovered the outer realities in question. Atoms and ether, with no properties but masses and velocities expressible by numbers, and paths expressible by analytic formulas, these at last are things over which the mathematico-logical network may be flung, and by supposing which instead of sensible phenomena science becomes yearly more able to manufacture for herself a world about which rational propositions may be framed. Sensible phe* nomena are pure delusions for the mechanical philosophy. The ' things ' and qualities we instinctively believe in dc not exist. The only realities are swarming solids in ever* lasting motion, undulatory or continued, whose expressionless and meaningless changes of position form the history of the world, and are deducible from initial collocations and habits of movement hypothetically assumed. Thousands of years ago men started to cast the chaos of nature's sequences and juxtapositions into a form that might seem intelligible. Many were their ideal prototypes of rational order : teleological and aesthetic ties between things, causal and substantial bonds, as well as logical and mathematical relations. The most promising of these ideal systems at first were of course the richer ones, the sentimental ones. The baldest and least promising were the mathematical ones; but the history of the latter' s application is a history of steadily advancing successes, whilst that of the sentimentally richer

be the results of experience would be such as experience violated. The first thing a Kantian ought to do is to discover forms of judgment to which no order in ' things ' runs parallel. These would indeed be features natire to the mind. I owe this remark to Herr A. Spir, in whose 'Denken und Wirklichkeit ' it is somewhere contained. I have myself already to some extent proceeded, and in the pages which follow shall proceed still farther, to show the originality of the mind's structure in this way.

systems is one of relative sterility and failure."'*' Take those aspects of phenomena which interest you as a human being most, and class the phenomena as perfect and imperfect, as ends and means to ends, as high and low, beautiful and ugly, positive and negative, harmonious and discordant, lit and unfit, natural and unnatural, etc., and barren are all your results. In the ideal world the kind ' precious ' has characteristic properties. What is precious should be preserved ; unworthy things should be sacrificed for its sake ; exceptions made on its account ; its preciousness is a reason for other things' actions, and the like. But none of these things need happen to your * precious ' object in the real world. Call the things of nature as much as you like by sentimental, moral, and aesthetic names, no natural consequences follow from the naming. They may be of the kinds you allege, but they are not of * the kind's kind *; and the last great system-maker of this sort, Hegel, was obliged explicitly to repudiate logic in order to make any inferences at all from the names he called things by.

But when you give things mathematical and mechanical names and call them just so many solids in just such positions, describing just such paths with just such velocities, all is changed. Your sagacity finds its reward in the verification by nature of all the deductions which you may next proceed to make. Your * things ' realize all the conseqitences of the names by which you classed them. The modern mechanico-physical philosophy of which we are all so proud, because it includes the nebular cosmogony, the conservation of energy, the kinetic theory of heat and

* Yet even so late as Berkeley's time one could write : " As in reading other books a wise man will choose to fix his thoughts on the sense and apply it to use, rather than lay them out in grammatical remarks on the language : so in perusing the volume of nature methinks it is beneath the dignity of the mind to affect an exactness in reducing each particular phenomenon to general rules, or showing how it follows from them. We should propose to ourselves nobler views, namely, to recreate and exalt the mind with a prospect of the beauty, order, extent, and variety of natural things : hence, by proper inferences, to enlarge our notions of the grandeur, wisdom, and beneficence of the Creator," etc, etc.. etc. (Princlplee of Human Knowledge, § 109.)

gases, etc., etc., begins by saying that the only facts are collocations and motions of primordial solids, and the only laws the changes of motion which changes in collocation bring. The ideal which this philosophy strives after is a mathematical world-formula, by which, if all the collocations and motions at a given moment were known, it would be possible to reckon those of any wished-for future moment, by simply considering the necessary geometrical, arithmetical, ana logical implications. Once we have the world in this bare shape, we can fling our net of a priori relations over all its terms, and pass from one of its phases to another by inward thought-necessity. Of course it is a world with a very minimum of rational stuff. The sentimental facts and relations are butchered at a blow. But the rationality yielded is so superbly complete inform that to many minds this atones for the loss, and reconciles the thinker to the notion of a purposeless universe, in which all the things and qualities men love, dulcissima mundi nominay are but illusioDs of our fancy attached to accidental clouds of dust which will be dissipated by the eternal cosmic weather as carelessly as they were formed.

The popular notion that * Science ' is forced on the mind ah extra^ and that our interests have nothing to do with its constructions, is utterly absurd. The craving to believe that the things of the world belong to kinds which are related by inward rationality together, is the parent of Science as well as of sentimental philosophy ; and the original investigator always preserves a healthy sense of how plastic the materials are in his hands. " Once for all," says Helmholtz in beginning that little work of his which laid the foundations of the 'conservation of energy,' "it is the task of the physical sciences to seek for laws by which particular processes in nature may be referred to general rules, and deduced from such again. Such rules (for example the laws of reflection or refraction of light, or that of Mariotte and Gay-Lussac for gas-volumes) are evidently nothing but generic-concepts for embracing whole classes of phenomena. The search for them is the business of the experimental division of our Science. Its theoretic division, on the other hand, tries to discover the unknown causes of processes from their visible effects ; tries to understand them by the law of causality. . . . The ultimate goal of theoretic physics is to find the last unchanging causes

of the processes in Nature. Whether all processes be really ascribable to such causes, whether, in other words, nature he completely intelligible, or whether there be changes which would elude the law of a necessary causality, and fall into a realm of spontaneity or freedom, is not here the place to determine ; but at any rate it is clear that the Science whose aim it is to make nature appear intelligible [die Natur zu begreifen] must start with the assumption of her intelligibility, and draw consequences in conformity with this assumption, until irrefutable facts show th© limitations of this method. . . . The postulate that natural phenomena must be reduced to changeless ultimate causes next shapes itself so that forces unchanged hy time must be found to be these causes. Now in Science we have already found portions of matter with changeless forces (indestructible qualities), and called them (chemical) elements. If, then, we imagine the world composed of elements with inalterable qualities, the only changes that can remain possible in such a world are spatial changes, i.e. movements, and the only outer relations which can modify the action of the forces are spatial too , or, in other words, the forces are motor forces dependent for their effect only on spatial relations. More exactly still : The phenomena of nature must be reduced to [zurilckgefiXhrt^ conceived as, classed as] motions of material points with inalterable motor forces acting according to space-relations alone. . . . But points have no mutual space-relations except their distance, . . . and a motor force which they exert upon each other can cause nothing but a change of distance — i.e. be an attractive or a repulsive force. . . . And its intensity can only depend on distance.

So that at last the task of Physics resolves itself into this, to refer phenomena to inalterable attractive and repulsive forces whose intensity varies with distance. The solution of this task would at the same time be the condition of Nature's complete intelligibility."* The subjective interest leading to the assumption could not be more candidly expressed. What makes the assumption • scientific ' and not merely poetic, what makes a Helmholtz and his kin discoverers, is that the things of Nature turn out to act as if they were of the kind assumed. They behave as such mere drawing and driving atoms would behave ; and so far as they have been distinctly enough translated into molecular terms to test the point, so far a certain fantastically ideal object, namely, the mathematical sum containing their mutual distances and velocities, is found to b© constant throughout all their movements. This sum ia oftlled the total energy of the molecules considered. Its con-

stancy or * conservation ' gives the name to the hypothesis of molecules and central forces from which it was logically deduced. Take any other mathematico-mechanical theory and it is the same. They are all translations of sensible experiences into other forms, substitutions of items between which ideal relations of kind, number, form, equality, etc., obtain, for items between which no such relations obtain ; coupled with declarations that the experienced form is false and th« ideal form true, declarations which are justified by the appearance of new sensible experiences at just those times and places at which we logically infer that their ideal correlates ought to be. Wave-hypotheses thus make us predict rings of darkness and color, distortions, dispersions, changes of pitch in sonorous bodies moving from us, etc. ; molecule-hypotheses lead to predictions of vapordensity, freezing point, etc., — all which predictions fall true.

Thus the world grows more orderly and rational to the mind, which passes from one feature of it to another by deductive necessity, as soon as it conceives it as made up of so few and so simple phenomena as bodies with no proper* ties but number and movement to and fro. But alongside of these ideal relations between terms which the world verifies, there are other ideal relations not as yet so verified. I refer to those propositions (no longer expressing mere results of comparison) which are formulated in such metaphysical and aesthetic axioms as " The Principle of things is one ; " " The quantity of existence is unchanged ; " " Nature is simple and invariable ; " ** Nature acts by the shortest ways ; " " Ex nihilo nihil Jit ; " " Nothing can be evolved which was not involved ; " " Whatever is in the efi'ect must be in the cause ; " "A thing can only work where it is ; " "A thing can only affect another of its own kind ; '* " Cessante causa, cessat et effectus ; " " Nature makes no leaps ; " " Things belong to discrete and permanent kinds ; '* ** Nothing is or happens without a reason ; " " The world is throughout rationally intelligible ; " etc.,

etc., etc. Such principles as these, which might be multiplied to satiety,* are properly to be called postulates of rationality y not propositions of fact. If nature did obey them, she would be pro tanto more intelligible ; and we seek meanwhile so to conceive her phenomena as to show that she does obey them. To a certain extent we succeed. For example, instead of the ' quantity of existence ' so vaguely postulated as unchanged, Nature allows us to suppose that curious sum of distances and velocities which for want of a better term we call * energy.' For the effect being 'contained in the cause,' nature lets us substitute ' the effect is the cause,' so soon as she lets us conceive both effect and cause as the same molecules, in two successive positions. — But all around these incipient successes (as all around the molecular world, so soon as we add to it as its ' effects ' those illusory * things ' of common-sense which we had to butcher for its sake), there still spreads a vast field of irrationalized fact whose items simply are together, and from one to another of which we can pass by no ideally ' rational ' way. It is not that these more metaphysical postulates of rationality are absolutely barren — though barren enough they were when used, as the scholastics used them, as immediate propositions of factf They have a fertility as

* Perhaps the most influential of all these postulates is that the nature of the world must be such that sweeping statements may be made about it. f Consider, e.g., the use of the axioms ' nemo potent supra seipsum/ and * nemo dat quod non habet,' in this refutation of 'Darwinism,' which I take from the much-used scholastic compendium of Logic and Metaphysics of Liberatore, 3d ed. (Rome, 1880): " Hsec hypothesis . . . aperte coutradicit principiis Metaphysicse, quse docent essentias rerum esse immutabiles, et effectum non posse superare causam. Et sane, quando, juxta Darwin, species inferior se evolvit in superiorem, unde trahit maiorem illam nobilitatem? Ex ejus carentia. At nihil dat quod non habet ; et minus gignere nequit plus, aut negatio positionem. Praeterea in transformatione quae fingitur, natura prions speciei, servatur aut destruitur? Si primum, mutatio erit tantum accidentalis, qualem reapse videmus in diversis stirpibus animantium. Sin alterum asseritur, ut reapse fert hypothesis darwiniana, res tenderet ad seipsam destruendam ; cum contra omnia naturaliter tendant ad sui conservationem, et nonnisi per actionem contrarii agentis corruant." It is merely a question of fact whether these ideally proper relations do or do not obtain between animal and vegetable ancestors and descendants. If they do not, what happens? simply this, that we cannot continue to class animal and vegetal facts under the kinds between which

ideals, and keep us uneasy and striving always to recast the world of sense until its lines become more congruent with theirs. Take for example the principle that ' nothing can happen without a cause.' We have no definite idea of what we mean by cause, or of what causality consists in. But the principle expresses a demand for some deeper sort of inward connection between phenomena than their merely habitual time-sequence seems to us to be. The word * cause ' is, in short, an altar to an unknown god ; an empty pedestal still marking the place of a hoped-for statue. Any ireally inward belonging-together of the sequent terms, if discovered, would be accepted as what the word cause was meant to stand for. So we seek, and seek ; and in the molecular systems we find a sort of inward belonging in the notion of identity of matter with change of collocation. Perhaps by still seeking we may find other sorts of inward belonging, even between the molecules and those * secondary qualities,' etc., which they produce upon our minds.

It cannot be too often repeated that the triumphant application of any one of our ideal systems of rational relations to the real world justifies our hope that other systems may be found also applicable. Metaphysics should take heart from the example of physics, simply confessing that hers is the longer task. Nature may be remodelled, nay, certainly will be remodelled, far beyond the point at present reached. Just how far ? — is a question which only the whole . future history of Science and Philosophy can answer.* Our task being Psychology, we cannot even cross the threshold of that larger problem.

those ideal relations obtain. Thus, we can no longer call animal breeds by the name of 'species '; cannot call generating a kind of 'giving,' or treat a descendant as an ' effect ' of his ancestor. The ideal scheme of terms and relations can remain, if you like ; but it must remain purely mental, and without application to life, which 'gangs its aiu gait' regardless of ideal schemes. Most of us, however, would prefer to doubt whether such abstract axioms as that ' a thing cannot tend to its own destruction ' express ideal relations of an important sort at all.

* Compare A. Riehl: Der Philosophische Kriticismus, Bd. ii. Thl. i Abschn. i. Cap. in. § 6. metaphysical principles as those just considered, there is a mental structure which expresses itself in The aesthetic principles are at bottom such axioms as that a note sounds good with its third and fifth, or that potatoes need salt. We are once for all so made that when certain impressions come before our mind, one of them will seem to call for or repel the others as its companions. To a certain extent the principle of habit will explain these aesthetic connections. When a conjunction is repeatedly experienced, the cohesion of its terms grows grateful, or at least their disruption grows unpleasant. But to explain oil aesthetic judgments in this way would be absurd ; for it is notorious how seldom natural experiences come up to our aesthetic demands. Many of the so-called metaphysical principles are at bottom only expressions of aesthetic feeling. Nature is simple and invariable ; makes no leaps, or makes nothing but leaps ; is rationally intelligible ; neither increases nor diminishes in quantity ; flows from one principle, etc., etc., — what do all such principles express save our sense of how pleasantly our intellect would feel if it had a Nature of that sort to deal with ? The subjectivity of which feeling is of course quite compatible with Nature also turning out objectively to be of that sort, later on.

The moral principles which our mental structure engenders are quite as little explicable in toto by habitual experiences having bred inner cohesions. Rightness is not mere usualness, wrongness not mere oddity, however numerous the facts which might be invoked to prove such identity. Nor are the moral judgments those most invariably and emphatically impressed on us by public opinion. The most characteristically and peculiarly moral judgments that a man is ever called on to make are in unprecedented cases and lonely emergencies, where no popular rhetorical maxims can avail, and the hidden oracle alone can speak ; and it speaks often in favor of conduct quite unusual, and suicidal as far as gaining popular approbation goes. The forces which conspire to this resultant are subtle harmonies and discords between the

elementary ideas which form the data of the case. Some of these harmonies, no doubt, have to do with habit ; but in respect to most of them our sensibility must assuredly be a phenomenon of supernumerary order, correlated with a brain-function quite as secondary as that which takes cognizance of the diverse excellence of elaborate musical compositions. No more than the higher musical sensibility can the higher moral sensibility be accounted for by the frequency with which outer relations have cohered.* Take judgments of justice or equity, for example. Instinctively, one judges everything differently, according as it pertains to one's self or to some one else. Empirically one notices that everybody else does the same. But little by little there dawns in one the judgment " nothing can be right for me which would not be right for another similarly placed ;" or " the fulfilment of my desires is intrinsically no more imperative than that of anyone else's ; " or " what it is reasonable that another should do for me, it is also reasonable that I should do for him ; " f and forthwith the whole mass of the habitual gets overturned. It gets seriously overturned only in a few fanatical heads. But its overturning is due to a back-door and not to a front-door process. Some minds are preternaturally sensitive to logical consistency and inconsistency. When they have ranked a thing under a kind, they must treat it as of that kind's kind, or feel all out of tune. In many respects we do class ourselves with other men, and call them and ourselves by a common name. They agree with us in having the same Heavenly Father, in not being consulted about their birth,