[526] 'Accidental' in the Darwinian sense, as belonging to a cycle of causation inaccessible to the present order of research.
[527] The passage is in § 207 of the Principles of Psychology, at the end of the chapter entitled 'Reason.' I italicize certain words in order to show that the essence of this explanation is to demand numerically frequent experiences. The bearing of this remark will later appear. (Cf. pp. 641-2, infra.)
[528] Principles of Biology, part iii. chaps. xi, xii.—Goltz and Loeb have found that dogs become mild in character when their occipital, and fierce when their frontal, brain-lobes are cut off. "A dog which originally was cross in an extreme degree, never suffering himself to be touched, and even refusing, after two days' fasting, to take a piece of bread from my hand, became, after a bilateral operation on the occipital lobes, perfectly trustful and harmless. He underwent five operations on these parts.... Each one of them made him more good-natured; so that at last (just as Goltz observed of his dogs) he would let other dogs take away the very bones which he was gnawing" (Loeb, Pflüger's Archiv, xxxix. 300). A course of kind treatment and training might have had a similar effect. But how absurd to call two such different causes by the same name, and to say both times that the beast's 'experience of outer relations' is what educates him to good-nature. This, however, is virtually what all writers do who ignore the distinction between the 'front-door' and the back-door' manners of producing mental change.
One of the most striking of these back-door affections is susceptibility to the charm of drunkenness. This (taking drunkenness in the broadest sense, as teetotalers use the word) is one of the deepest functions of human nature. Half of both the poetry and the tragedy of human life would vanish if alcohol were taken away. As it is, the thirst for it is such that in the United States the cash-value of its sales amounts to that of the sales of meat and of bread put together. And yet what ancestral 'outer relation' is responsible for this peculiar reaction of ours? The only 'outer relation' could be the alcohol itself, which, comparatively speaking, came into the environment but yesterday, and which, so far from creating, is tending to eradicate, the love of itself from our mental structure, by letting only those families of men survive in whom it is not strong. The love of drunkenness is a purely accidental susceptibility of a brain, evolved for entirely different uses, and its causes are to be sought in the molecular realm, rather than in any possible order of 'outer relations.'
[529] Mr. Grant Allen, in a brilliant article entitled Idiosyncrasy (Mind, viii. 498), seeks to show that accidental morphological changes in the brain cannot possibly be imagined to result in any mental change of a sort which would fit the animal to its environment. If spontaneous variation ever works on the brain, its product, says Mr. Allen, ought to be an idiot or a raving madman, not a minister and interpreter of Nature. Only the environment can change us in the direction of accommodation to itself. But I think we ought to know a little better just what the molecular changes in the brain are on which thought depends, before we talk so confidently about what the effect can be of their possible variations. Mr. Allen, it should be said, has made a laudable effort to conceive them distinctly. To me his conception remains too purely anatomical. Meanwhile this essay and another by the same author in the Atlantic Monthly are probably as serious attempts as any that have been made towards applying the Spencerian theory in a radical way to the facts of human history.
[530] In my own previous chapters on habit, memory, association, and perception, justice has been done to all these facts.
[531] "The order of nature, as perceived at a first glance, presents at every instant a chaos followed by another chaos. We must decompose each chaos into single facts. We must learn to see in the chaotic antecedent a multitude of distinct antecedents, in the chaotic consequent a multitude of distinct consequents. This, supposing it done, will not of itself tell us on which of the antecedents each consequent is invariably attendant. To determine that point, we must endeavor to effect a separation of the facts from one another, not in our minds only, but in nature. The mental analysis, however, must take place first. And every one knows that in the mode of performing it, one intellect differs immensely from another." (J. S. Mill, Logic, bk. iii. chap. vii. § 1.)
[532] I quote from an address entitled 'Reflex Action and Theism,' published in the 'Unitarian Review' for November 1881, and translated in the Critique Philosophique for January and February 1882. "The conceiving or theorizing faculty works exclusively for the sake of ends that do not exist at all in the world of the impressions received by way of our senses, but are set by our emotional and practical subjectivity. It is a transformer of the world of our impressions into a totally different world, the world of our conception; and the transformation is effected in the interests of our volitional nature, and for no other purpose whatsoever. Destroy the volitional nature, the definite subjective purposes, preferences, fondness for certain effects, forms, orders, and not the slightest motive would remain for the brute order of our experience to be remodelled at all. But, as we have the elaborate volitional constitution we do have, the remodelling must be effected, there is no escape. The world's contents are given to each of us in an order so foreign to our subjective interests that we can hardly by an effort of the imagination picture to ourselves what it is like. We have to break that order altogether, and by picking out from it the items that concern us, and connecting them with others far away, which we say 'belong' with them, we are able to make out definite threads of sequence and tendency, to foresee particular liabilities and get ready for them, to enjoy simplicity and harmony in the place of what was chaos. Is not the sum of your actual experience taken at this moment and impartially added together an utter chaos? The strains of my voice, the lights and shades inside the room and out, the murmur of the wind, the ticking of the clock, the various organic feelings you may happen individually to possess, do these make a whole at all? Is it not the only condition of your mental sanity in the midst of them that most of them should become non-existent for you, and that a few others—the sounds, I hope, which I am uttering—should evoke from places in your memory, that have nothing to do with this scene, associates fitted to combine with them in what we call a rational train of thought?—rational because it leads to a conclusion we have some organ to appreciate. We have no organ or faculty to appreciate the simply given order. The real world as it is given at this moment is the sum total of all its beings and events now. But can we think of such a sum? Can we realize for an instant what a cross-section of all existence at a definite point of time would be? While I talk and the flies buzz, a sea gull catches a fish at the mouth of the Amazon, a tree falls in the Adirondack wilderness, a man sneezes in Germany, a horse dies in Tartary, and twins are born in France. What does that mean? Does the contemporaneity of these events with each other and with a million more as disjointed as they form a rational bond between them, and unite them into anything that means for us a world? Yet just such a collateral contemporaneity, and nothing else, is the real order of the world. It is an order with which we have nothing to do but to get away from it as fast as possible. As I said, we break it: we break it into histories, and we break it into arts, and we break it into sciences; and then we begin to feel at home. We make ten thousand separate serial orders of it. On any one of these, we may react as if the rest did not exist. We discover among its parts relations that were never given to sense at all,—mathematical relations, tangents, squares, and roots and logarithmic functions,—and out of an infinite number of these we call certain ones essential and lawgiving, and ignore the rest. Essential these relations are, but only for our purpose, the other relations being just as real and present as they; and our purpose is to conceive simply and to foresee. Are not simple conception and prevision subjective ends, pure and simple? They are the ends of what we call science; and the miracle of miracles, a miracle not yet exhaustively cleared up by any philosophy, is that the given order lends itself to the remodelling. It shows itself plastic to many of our scientific, to many of our æsthetic, to many of our practical purposes and ends." Cf. also Hodgson: Philos. of Refl., ch. v; Lotze: Logik, §§ 342-351; Sigwart: Logik, §§ 60-63, 105.
[533] In an article entitled 'Great Men, Great Thoughts, and the Environment,' published in the Atlantic Monthly for October 1880, the reader will find some ampler illustrations of these remarks. I have there tried to show that both mental and social evolution are to be conceived after the Darwinian fashion, and that the function of the environment properly so called is much more that of selecting forms, produced by invisible forces, than producing of such forms,—producing being the only function thought of by the pre-Darwinian evolutionists, and the only one on which stress is laid by such contemporary ones as Mr. Spencer and Mr. Allen.
[534] "It is perfectly true that our world of experience begins with such associations as lead us to expect that what has happened to us will happen again. These associations lead the babe to look for milk from its nurse and not from its father, the child to believe that the apple he sees will taste good; and whilst they make him wish for it, they make him fear the bottle which contains his bitter medicine. But whereas a part of these associations grows confirmed by frequent repetition, another part is destroyed by contradictory experiences; and the world becomes divided for us into two provinces, one in which we are at home and anticipate with confidence always the same sequences; another filled with alternating, variable, accidental occurrences....
"Accident is, in a wide sphere, such an every-day matter that we need not be surprised if it sometimes invades the territory where order is the rule. And one personification or another of the capricious power of chance easily helps us over the difficulties which further reflection might find in the exceptions. Yes, indeed, Exception has a peculiar fascination; it is a subject of astonishment, a θαῦμα, and the credulity with which in this first stage of pure association we adopt our supposed rules is matched by the equal credulity with which we adopt the miracles that interfere with them.
"The whole history of popular beliefs about nature refutes the notion that the thought of an universal physical order can possibly have arisen through the purely passive reception and association of particular perceptions. Indubitable as it is that all men infer from known cases to unknown, it is equally certain that this procedure, if restricted to the phenomenal materials that spontaneously offer themselves, would never have led to the belief in a general uniformity, but only to the belief that law and lawlessness rule the world in motley alternation. From the point of view of strict empiricism nothing exists but the sum of particular perceptions with their coincidences on the one hand, their contradictions on the other.
"That there is more order in the world than appears at first sight is not discovered till the order is looked for. The first impulse to look for it proceeds from practical needs: where ends must be attained, we must know trustworthy means which infallibly possess a property or produce a result. But the practical need is only the first occasion for our reflection on the conditions of a true knowledge; even were there no such need, motives would still be present to carry us beyond the stage of mere association. For not with an equal interest, or rather with an equal lack of interest, does man contemplate those natural processes in which like is joined to like, and those in which like and unlike are joined; the former processes harmonize with the conditions of his thinking, the latter do not; in the former his concepts, judgments, inferences apply to realities, in the latter they have no such application. And thus the intellectual satisfaction which at first comes to him without reflection, at last excites in him the conscious wish to find realized throughout the entire phenomenal world those rational continuities, uniformities, and necessities which are the fundamental element and guiding principle of his own thought." (C. Sigwart: Logik, ii. 380-2.)
[535] Cf. Hodgson: Philosophy of Reflection, book ii, chap. v.
[536] The aspiration to be 'scientific' is such an idol of the tribe to the present generation, is so sucked in with his mother's milk by every one of us, that we find it hard to conceive of a creature who should not feel it, and harder still to treat it freely as the altogether peculiar and one-sided subjective interest which it is. But as a matter of fact, few even of the cultivated members of the race have shared it; it was invented but a generation or two ago. In the middle ages it meant only impious magic; and the way in which it even now strikes orientals is charmingly shown in the letter of a Turkish cadi to an English traveller asking him for statistical information, which Sir A. Bayard prints at the end of his 'Nineveh and Babylon.' The document is too full of edification not to be given in full. It runs thus:
"My Illustrious Friend, and Joy of my Liver!
"The thing you ask of me is both difficult and useless. Although I have passed all my days in this place, I have neither counted the houses nor inquired into the number of the inhabitants; and as to what one person loads on his mules and the other stows away in the bottom of his ship, that is no business of mine. But, above all, as to the previous history of this city, God only knows the amount of dirt and confusion that the infidels may have eaten before the coming of the sword of Islam. It were unprofitable for us to inquire into it.
"O my soul! O my lamb! seek not after the things which concern thee not. Thou camest unto us and we welcomed thee: go in peace.
"Of a truth thou hast spoken many words; and there is no harm done, or the speaker is one and the listener is another. After the fashion of thy people thou hast wandered from one place to another, until thou art happy and content in none. We (praise be to God) were born here, and never desire to quit it. Is it possible, then, that the idea of a general intercourse between mankind should make any impression on our understandings? God forbid!
"Listen, O my son! There is no wisdom equal unto the belief in God! He created the world, and shall we liken ourselves unto Him in seeking to penetrate into the mysteries of His creation? Shall we say, Behold this star spinneth round that star, and this other star with a tail goeth and cometh in so many years! Let it go! He from whose hand it came will guide and direct it.
"But thou wilt say unto me, Stand aside, O man, for I am more learned than thou art, and have seen more things. If thou thinkest that thou art in this respect better than I am, thou art welcome. I praise God that I seek not that which I require not. Thou art learned in the things I care not for; and as for that which thou hast seen, I spit upon it. Will much knowledge create thee a double belly, or wilt thou seek Paradise with thine eyes?
"O my friend! if thou wilt be happy, say, There is no God but God! Do no evil, and thus wilt thou fear neither man nor death: for surely thine hour will come!
"The meek in spirit (El Fakir)
"Imaum Ali Zadi."
[537] "Though a man in a fever should from sugar have a bitter taste which at another time would produce a sweet one, yet the idea of bitter in that man's mind would be as clear and distinct from the idea of sweet as if he had tasted only gall. Nor does it make any more confusion between the two ideas of sweet and bitter that the same sort of body produces at one time one and at another time another idea by the taste, than it makes a confusion in two ideas of white and sweet, or white and round, that the same piece of sugar produces them both in the mind at the same time." Locke's Essay, bk. ii. ch. xi. § 3.
[538] Cf. Bradley, Logic, p. 226.
[539] This apprehension of them as forming a single system is what Mr. Bradley means by the act of construction which underlies all reasoning. The awareness, which then supervenes, of the additional relation of which I speak in the next paragraph of my text, is what this author calls the act of inspection. Cf. Principles of Logic, bk. ii. pt. i. chap. iii.
[540] Realities fall under this only so far as they prove to be the same. So far as they cannot be substituted for each other, for the purpose in hand, so far they are not the same; though for other purposes and in other respects they might be substituted, and then be treated as the same. Apart from purpose, of course, no realities ever are absolutely and exactly the same.
[541] A mind, in other words, which has got beyond the merely dichotomic style of thought which Wundt alleges to be the essential form of human thinking (Physiol. Psych., ii. 312).
[542] Said to be expressed by Grassman in the fundamental Axiom of Arithmetic (a + b) + 1 = a + (b + 1).
[543] Compare Helmholtz's more technically expressed Essay Zählen u. Messen, in the Philosophische Aufsätze, Ed. Zeller gewidmet (Leipzig, 1887), p. 17.
[544] For the original statements, cf. J. S. Mill's Logic, bk. ii. chap. vi. §§ 2, 3; and bk. iii. chap. xxiv. § 5.
[545] The subdivision itself consumes none of the space. In all practical experience our subdivisions do consume space. They consume it in our geometrical figures. But for simplicity's sake, in geometry we postulate subdivisions which violate experience and consume none of it.
[546] Cf. A. de Morgan: Syllabus of a proposed System of Logic (1860), pp. 46-56.
[547] Cf. Locke's Essay, bk. ii. chap. xvii. § 6.
[548] 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 being the case, the question "at what point does the new state of mind cease to be 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 nugæ 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 between which a priori relations obtain. The analytic-synthetic 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 Denken und Wirklichkeit, I think, but I cannot now find the page.
[549] Book iv. chaps. ix. § 1; vii. 14.
[550] Chap. v. §§ 6, 8.
[551] 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 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 native 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.
[552] 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. (Principles of Human Knowledge, § 109.)
[553] Die Erhaltung der Kraft (1847), pp. 2-6.
[554] 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.
[555] Consider, e.g., the use of the axioms 'nemo potest 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): "Hæc hypothesis... aperte contradicit principiis Metaphysicæ, quæ 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. Præterea in transformatione quæ fingitur, nature prioris 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 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 ain 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.
[556] Compare A. Riehl: Der Philosophische Kriticismus, Bd. ii. Thl. i Abschn. i. Cap. iii. § 6.
[557] As one example out of a thousand of exceptionally delicate idiosyncrasy in this regard, take this: "I must quit society. I would rather undergo twice the danger from beasts and ten times the danger from rocks. It is not pain, it is not death, that I dread,—it is the hatred of a man; there is something in it so shocking that I would rather submit to any injury than incur or increase the hatred of a man by revenging it.... Another sufficient reason for suicide is that I was this morning out of temper with Mrs. Douglas (for no fault of hers). I did not betray myself in the least, but I reflected that to be exposed to the possibility of such an event once a year, was evil enough to render life intolerable. The disgrace of using an impatient word is to me overpowering." (Elton Hammond, quoted in Henry Crabb Robinson's Diary, vol. i. p. 424.)
[558] Compare H. Sidgwick, Methods of Ethics, bk. iii. chap. xiii. § 3.
[559] A gentleman told me that he had a conclusive argument for opening the Harvard Medical School to women. It was this: "Are not women human?"—Which major premise of course had to be granted. "Then are they not entitled to all the rights of humanity?" My friend said that he had never met anyone who could successfully meet this reasoning.
[560] You reach the Mephistophelian point of view as well as the point of view of justice by treating cases as if they belonged rigorously to abstract classes. Pure rationalism, complete immunity from prejudice, consists in refusing to see that the case before one is absolutely unique. It is always possible to treat the country of one's nativity, the house of one's fathers, the bed in which one's mother died, nay, the mother herself if need be, on a naked equality with all other specimens of so many respective genera. It shows the world in a clear frosty light from which all fuliginous mists of affection, all swamp-lights of sentimentality, are absent. Straight and immediate action becomes easy then—witness a Napoleon's or a Frederick's career. But the question always remains, "Are not the mists and vapors worth retaining?" The illogical refusal to treat certain concretes by the mere law of their genus has made the drama of human history. The obstinate insisting that tweedledum is not tweedledee is the bone and marrow of life. Look at the Jews and the Scots, with their miserable factions and sectarian disputes, their loyalties and patriotisms and exclusions,—their annals now become a classic heritage, because men of genius took part and sang in them. A thing is important if any one think it important. The process of history consists in certain folks becoming possessed of the mania that certain special things are important infinitely, whilst other folks cannot agree in the belief. The Shah of Persia refused to be taken to the Derby Day, saying "It is already known to me that one horse can run faster than another." He made the question "which horse?" immaterial. Any question can be made immaterial by subsuming all its answers under a common head. Imagine what college ball-games and races would be if the teams were to forget the absolute distinctness of Harvard from Yale and think of both as One in the higher genus College. The sovereign road to indifference, whether to evils or to goods, lies in the thought of the higher genus. "When we have meat before us," says Marcus Aurelius, seeking indifference to that kind of good, "we must receive the impression that this is the dead body of a fish, and this is the dead body of a bird or of a pig; and again that this Falernian is only a little grape-juice, and this purple robe some sheep's wool dyed with the blood of a shell-fish. Such, then, are these impressions, and they reach the things themselves and penetrate them, and we see what kind of things they are. Just in the same way ought we to act through life, and where there are things which appear most worthy of our approbation, we ought to lay them bare and look at their worthlessness and strip them of all the words by which they are exalted." (Long's Translation, vi. 13.)
[561] "An sich, in seinem eignen Wesen, ist jedes reale Object mit sich selbst identisch und unbedingt"—that is, the "allgemeinste Einsicht a priori" and the "allgemeinste aus Erfahrung" is "Alles erkennbare ist bedingt." (A. Spir: Denken und Wirklichkeit. Compare also Herbart and Hegel.)
[562] Philosophie Zoölogique, 3me partie, chap. v., 'de l'Instinct.'
[563] It should be said that Mr. Spencer's most formal utterance about instinct is in his Principles of Psychology, in the chapter under that name. Dr. Romanes has reformulated and criticised the doctrine of this chapter in his Mental Evolution in Animals, chapter xvii. I must confess my inability to state its vagueness in intelligible terms. It treats instincts as a further development of reflex actions, and as forerunners of intelligence,—which is probably true of many. But when it ascribes their formation to the mere 'multiplication of experiences,' which, at first simple, mould the nervous system to 'correspond to outer relations' by simple reflex actions, and, afterwards complex, make it 'correspond' by 'compound reflex actions,' it becomes too mysterious to follow without more of a key than is given. The whole thing becomes perfectly simple if we suppose the reflex actions to be accidental inborn idiosyncrasies preserved.
[564] This account of acquisitiveness differs from our own. Without denying the associationist account to be a true description of a great deal of our proprietary feeling, we admitted in addition an entirely primitive form of desire. (See above, p. 420 ff.) The reader must decide as to the plausibilities of the case. Certainly appearances are in favor of there being in us some cupidities quite disconnected with the ulterior uses of the things appropriated. The source of their fascination lies in their appeal to our æsthetic sense, and we wish thereupon simply to own them. Glittering, hard, metallic, odd, pretty things; curious things especially; natural objects that look as if they were artificial, or that mimic other objects,—these form a class of things which human beings snatch at as magpies snatch rags. They simply fascinate us. What house does not contain some drawer or cupboard full of senseless odds and ends of this sort, with which nobody knows what to do, but which a blind instinct saves from the ash-barrel? Witness people returning from a walk on the sea-shore or in the woods, each carrying some lusus naturæ in the shape of stone or shell, or strip of bark or odd-shaped fungus, which litter the house and grow daily more unsightly, until at last reason triumphs over blind propensity and sweeps them away.
[565] Review of Bain in H. Spencer: Illustrations of Universal Progress (New York, 1864), pp. 311, 315.
[566] Ribot: De l'Herédité, 2me éd. p. 26.
[567] Quoted (without reference) in Spencer's Biology, vol. i. p. 247.
[568] Expression of Emotions (N. Y.), p. 287.
[569] 'Adaptive' changes are those produced by the direct effect of outward conditions on an organ or organism. Sunburned complexion, horny hands, muscular toughness, are illustrations.
[570] For these and other facts cf. Th. Ribot: De l'Hérédité; W. B. Carpenter: Contemporary Review, vol. 21, p. 295, 779, 867; H. Spencer: Princ. of Biol. pt. ii. ch. v, viii, ix, x; pt. iii. ch. xi, xii; C. Darwin: Animals and Plants under Domestication, ch. xii, xiii. xiv; Sam'l Butler: Life and Habit; T. A. Knight: Philos. Trans. 1837; E. Dupuy: Popular Science Monthly, vol. xi. p. 332; F. Papillon; Nature and Life, p. 330; Crothers, in Pop. Sci. M., Jan. (or Feb.) 1889.
[571] [Because, being exhibited by neuter insects, the effects of mere practice cannot accumulate from one generation to another.—W. J.]
[572] Origin of Species, chap. vii.
[573] Princ. of Psychol., ii. 561.
[574] Ibid. p. 263.
[575] Ueber die Vererbung (Jena, 1883). Prof. Weismann's Essays on Heredity have recently (1889) been published in English in a collected form.
[576] Best expressed in the Essay on the Continuitat des Keimplasmas (1885).