"Its cogitative faculties immersedIn cogibundity of cogitation,"
"Its cogitative faculties immersedIn cogibundity of cogitation,"
"Its cogitative faculties immersed
In cogibundity of cogitation,"
till it evolves from the depth of its consciousness something like an idealistic theory of sound. This hypothesis, Mr. Huxley in reply to his piano, refutes, first by an appeal to the material substance of the instrument itself; and secondly to the existence of a musician who plays upon it. Will he permit us to accept in like manner the fact of our own nobler subsistence, and also the being of One Who attunes its secret heart-strings to notes of sublime melody?
The monsters aforecited irresistibly remind us of a repartee of Goldsmith's. He wittily said that Dr. Johnson would make little fishes talk like great whales. Had they done so it may be doubted whether the Doctor's idolatrous biographer would have discovered a minnowy mind beneath their Johnsonian utterances. And we confess to a difficulty of our own. The righteous clock is indeed genuinely Huxleian, but what shall we say of his mechanical logic, his piano, and his death-watches? By way of illustrating our perplexity let us suppose some rural sexton to mix up his own instincts with those of a biological burying beetle. The destiny of all flesh would naturally be determined in the first place by a decent covering of earth. But what about its final end? Would that be an aldermanic beetle feast or aResurgam?
Think again how a member of the Society for the Prevention of Cruelty to Animals might breathe a benevolent spirit into a much employed dissecting knife. The sharp thing would certainly entertain a repugnance to the horrors of vivisection. There might also be a denial of its utility based on the scalpel's personal experience, or perhaps a moral doubt as to whether such means are justified by the ends proposed. Would Mr. Huxley listen to the remonstrance and undertake to lift up his powerful voice at Paris or at Berlin besides a few other remote places which need not be particularized?
Or finally what ear would he lend to a magnifying glass accustomed to habits of observation and possessed by the soul of Spurzheim. Suppose it should affirm that a slice of Destructiveness is recognizably different in structure from a section of Benevolence; and Acquisitiveness in like manner distinguishable from Ideality! Yet a humanitarian scalpel or Spurzheim magnifying glass may be thought a Huxleian phenomenon.
A truce to such mongrel meditations. We gladly turn away from them and continue our quotations from the Professor's sentiments deliveredin propria persona, recommencing at the place where our last extract broke off. (p. 307.)
"The teleological and the mechanical views of nature, are not necessarily, mutually exclusive. On the contrary, the more purely a mechanist the speculator is, the more firmly does he assume primordial molecular arrangement, of which all the phenomena of the universe are the consequences; and the more completely is he thereby at the mercy of the teleologist who can always defy him to disprove that this primordial molecular arrangement was not intended to evolve the phenomena of the universe."
We quite agree with Mr. Huxley that Mechanism never can exclude final causes, and that a thorough-going theory of Evolution (taken apart from its excrescences) disables the theorist from all real disproof of intention or Design. As we said before, the question of how the theorist's primordial arrangement began, is left unprovided for. And if a beginning, so certainly anend. The more steadily the first state of the Universe conceivable by Science is contemplated, the wider and more determinate the view thus taken, the more evident it becomes that the ground occupied by Natural Theology is not fenced off by the iron pale of Mechanism. The fencer is (as Huxley says) "at the mercy of the Teleologist."
The Professor's next sentence deserves careful consideration—"On the other hand, if the teleologists assert that this, that, or the other result of the working of any part of the mechanism of the universe isits purpose and final cause, the mechanist can always inquire how he knows that it is more than an unessential incident—the mere ticking of the clock, which he mistakes for its function."
How far this criticism holds good of many well-meant treatises filled with special instances of Design is a question for candid consideration. Meantime the whole sentence amounts to this conclusion:—We must distinguish between such wide arguments as Baden Powell's, and the details of certain writers who have dealt with what they thought good examples and illustrations of a grand universal principle. And that such is Mr. Huxley's meaning we may perceive from another paragraph immediately preceding our first extract. (p. 305.)
"In more than one place, Professor Haeckel enlarges upon the service which theOrigin of Specieshas done, in favouring what he terms the 'causal or mechanical' view of living nature as opposed to the 'teleological or vitalistic' view. And no doubt it is quite true that the doctrine of Evolution is the most formidable opponent of all the commoner and coarser forms of Teleology. But perhaps the most remarkable service to the philosophy of Biology rendered by Mr. Darwin is the reconciliation of Teleology and Morphology, and the explanation of the facts of both which his views offer."
Now, such being the state of facts, we may refuse to say with Huxley that the following question (asked p. 307) is "not irrational." "Why trouble oneself about matters which are out of reach, when the working of the mechanism itself, which is of infinite practical importance, affords scope for all our energies?"
We cannot forego our trouble, for two reasons.First, according to the statements before quoted, Mr. Darwin's researches have improved the case for Teleology. Advocates of Design may therefore take courage, they have gained a potent alliance.Secondly, "the practical working of the Mechanism itself" is very far, we think, from being our All—so far, indeed, that it sinks into insignificance compared with the hope of Immortality. Our highest interest lies in gathering such information as we can regarding Him with Whom we have to do as the Arbiter of our future existence. Above all things, we desire Him to be our Father and our Friend. Perchance His attributes are not matters out of reach. He may be very near to every one of us, if we are indeed His Offspring.
Another opinion of Professor Huxley's is of great auxiliary value to the argument from Design. The structures mentioned have to some minds appeared as its most serious difficulties. "Professor Haeckel," he explains, "has invented a new and convenient name, 'Dysteleology,' for the study of the 'purposelessnesses' which areobservable in living organisms—such as the multitudinous cases of rudimentary and apparently useless structures. I confess, however, that it has often appeared to me that the facts of Dysteleology cut two ways. If we are to assume, as evolutionists in general do, that useless organs atrophy, such cases as the existence of lateral rudiments of toes, in the foot of a horse, place us in a dilemma. For, either these rudiments are of no use to the animal, in which case, considering that the horse has existed in its present form since the Pliocene epoch, they surely ought to have disappeared; or they are of some use to the animal, in which case they are of no use as arguments against Teleology." (p. 307.) It would be hard to overestimate the value of this opinion, still more hard to overrate its genuine and outspoken honesty.
Mr. Huxley places at the end of his recent volume a passage from Bishop Berkeley which we will venture to borrow by way of conclusion to this lengthy note:—
"You see, Hylas, the water of yonder fountain, how it is forced upwards in a round column to a certain height, at which it breaks and falls back into the basin from whence it rose; its ascent as well as its descent proceeding from the same uniform law or principle of gravitation. Just so, the same principles which, at first view, lead to scepticism, pursued to a certain point, bring men back to common sense."
Adsit omen!May it be even thus with our large-minded Professor and with all other sovereign princes of Biology—Ἵλεως Ἀσκληπίος!
CONDITIONS OF HUMAN KNOWLEDGE.
"The words which the great German poet put into the mouth of Mephistopheles when describing himself to Faust, afford perhaps the most concise and forcible statement of what we may call the anti-scientific spirit:—
'Ich bin der Geist der stets verneint,Dem alles, was entsteht, zuwider ist.'
'Ich bin der Geist der stets verneint,Dem alles, was entsteht, zuwider ist.'
'Ich bin der Geist der stets verneint,
Dem alles, was entsteht, zuwider ist.'
The true spirit of science is certainly affirmative, not negative; for, as I mentioned just now, its history teaches us that the development of our knowledge usually takes place through two or more simultaneous ideas of the same phenomenon, quite different from one another, both of which ultimately prove to be parts of some more general truth; so that a confident belief in one of those ideas does not involve or justify a denial of the others."—Address of the President of the British Association, 1873-4. p. 13.
"Philosophy is but wise and disciplined thought upon the subjects on which all men think. The minds of men, left to their own natural working, will never cease to think on these things; and if Philosophy should cease to attempt to think wisely on them, she abandons her position as a guide. She has been to blame for the carelessness of her procedure, for the overweeningness of her pretensions. But the remedy is soberness, not scepticism. Is it, after all, an evil, that in some directions we fail to attain certainty by mere thinking?... As in nature, the picture you see is not broad light and dark, but a thousand tender tones and hues melting into each other, and vibrating together between the light and dark: so is the mind of man." Archbishop of York—onThe limits of Philosophical Inquiry, pp. 25-26.
"To theknowledgeof the most contemptibleeffectin nature, 'tis necessary to know the wholeSyntaxof Causes, and their particularcircumstances, andmodesof action. Nay, weknow nothing, till weknow ourselves, which are the summary of all the world without us, and theIndexof the Creation." Glanvill,Vanity of Dogmatizing, Chap. xxii. Ed. 1. p. 217.
"A branching channel, with a mazy flood?The purple stream that through my vessels glides,Dull and unconscious flows, like common tides:The pipes through which the circling juices stray,Are not that thinking I, no more than they:This frame compacted with transcendent skill,Of moving joints obedient to my will,Nurs'd from the fruitful glebe, like yonder tree,Waxes and wastes; I call it mine, not me."Dr. Arbuthnot.
"A branching channel, with a mazy flood?The purple stream that through my vessels glides,Dull and unconscious flows, like common tides:The pipes through which the circling juices stray,Are not that thinking I, no more than they:This frame compacted with transcendent skill,Of moving joints obedient to my will,Nurs'd from the fruitful glebe, like yonder tree,Waxes and wastes; I call it mine, not me."Dr. Arbuthnot.
"A branching channel, with a mazy flood?The purple stream that through my vessels glides,Dull and unconscious flows, like common tides:The pipes through which the circling juices stray,Are not that thinking I, no more than they:This frame compacted with transcendent skill,Of moving joints obedient to my will,Nurs'd from the fruitful glebe, like yonder tree,Waxes and wastes; I call it mine, not me."Dr. Arbuthnot.
"A branching channel, with a mazy flood?
The purple stream that through my vessels glides,
Dull and unconscious flows, like common tides:
The pipes through which the circling juices stray,
Are not that thinking I, no more than they:
This frame compacted with transcendent skill,
Of moving joints obedient to my will,
Nurs'd from the fruitful glebe, like yonder tree,
Waxes and wastes; I call it mine, not me."
Dr. Arbuthnot.
"'To the eye of vulgar Logic,' says he, 'what is man? An omnivorous Biped that wears Clothes. To the eye of Pure Reason what is he? A soul, a Spirit, and divine Apparition. Round his mysterious Me, there lies, under all those wool-rags, a Garment of Flesh (or of Senses), contextured in the Loom of Heaven; whereby he is revealed to his like, and dwells with them in UNION and DIVISION; and sees and fashions for himself a Universe, with azure Starry Spaces, and long Thousands of Years. Deep-hidden is he under that strange Garment; amid Sounds and Colours and Forms, as it were, swathed in, and inextricably over-shrouded: yet it is skywoven, and worthy of a God. Stands he not thereby in the centre of Immensities, in the conflux of Eternities? He feels; power has been given him to Know, to Believe; nay does not the spirit of Love, free in its celestial primeval brightness, even here, though but for moments, look through? Well said Saint Chrysostom, with his lips of gold, "the trueShekinahis Man:" where else is theGod's-Presencemanifested not to our eyes only, but to our hearts, as in our fellow man?'"—Sartor Resartus, Chap. x. Pure Reason.
SYNOPSIS OF CHAPTER III.
This Chapter may be characterized as a parallel between the difficulties alleged to be fatal against Theism, and the difficulties attaching to very various departments of human knowledge, embracing its most necessary and its most certainly accepted kinds. From this parallel the conclusion becomes evident, that whoever accepts one set of truths cannot be debarred by these or similar difficulties from accepting the higher truth likewise. That such an acceptance is natural and valid appears further evident from the fact that a knowledge of God belongs to the class of Practical beliefs, and is enforced by the same reasonable necessity. This topic forms the transition to Chapter IV. on "Our Reasonable Beliefs."
The same inferences are also stated in adestructiveform,e.g., Should a thinker choose to deny the possibility of Theism, he ought (if consistent) to deny all those truths which stand or fall by a parallel set of reasonings. But by doing this he lands himself in a state of doubt, so extreme and thorough, that the whole Universe becomes a rayless blank.
A corollary is added on Materialism.
Analysis—Man the interpreter of Nature. Naturegivesby answering our interrogations; these must depend on our powers of assimilating knowledge. Some questions inevitable,e.g., What are the first grounds of Truth?
Has Man any faculty of apprehending the Infinite? Can we know our own Personality or that of others?—or any Thing in itself? Inference against Scepticism based on human ignorance.
Fallacy of the Unthinkable or Inconceivable. Ideas of Self and not-Self, inexplicable, yet undoubted. From things as they are, let us turn to things as they appear. How do we perceive, hear, see?
Perception as an instrument of Intelligence, inscrutable. We acknowledge the insoluble mystery but accept the fact.
Marvels of eyesight, and their problems. How much and what do we see? Comparison with Sound;—Form, Colour, Tone. Evidence on which we receive sense impressions. Comparison between healthy and diseased sensations,—between our organs of sense and those of animals. We soon arrive at a twilight territory of knowledge and can explain no more.
Imperfections in our powers of Verification. How great is the subjective Element in our perceptions? Idealism,—most difficult to answer when most extreme. Philosophic denial of all proof of external things as distinguished from Mind (e.g., by Mill). Fact-knowledge, and absurdities involved in the ordinary method of defining and alleging Facts. Polar tendencies of Phenomenalism which take the shapes of Idealism and Positivism, resulting in Nihilism or Indifferentism. The end of these things! Mr. Herbert Spencer on Theology, compared with Mr. Huxley, and criticized by Mr. J. Martineau, who denies that the Unknowable can be any object of religious feeling,—a protest strongly maintained by Mr. J. S. Mill.
The difficulties attending every kind of knowledge paralleled with the difficulties alleged against Theism. If the Inexplicable be also the Unknowable, there is an end to all knowledge. We cannot predicate veracity of our human Mind, we cannot even know that we know anything. Mr. J. S. Mill accepts Mind as an inexplicable Fact underlying all other Facts and Beliefs. WemustacceptultimateTruths.
Transition to Chapter IV. on the affirmative evidence for our Reasonable Beliefs.
Corollary on Materialism. Far more difficult than its antithesis. Conclusion to be drawn from these difficulties.
Additional Notes and Illustrations.
A.—Account of some theories respecting our Personal Identity.
B.—Helmholtz, Popular Lectures on Recent Progress of the Theory of Vision.
C.—Helmholtz on Specialties of Sensibility.
D.—Popular account of Pure Idealism with critical remarks.
E.—On the Relations of Fact and Theory.
F.—On the "Unknowable."
G.—Mr. J. S. Mill as an Independent Moralist.
Additions to Corollary.
Note H.—Archebiosis, or Spontaneous Generation. I.—On Materialism.
CHAPTER III.
CONDITIONS OF HUMAN KNOWLEDGE.
Is the great Book of Nature—the world we live in—a closed or open book to Man? On this question all have thought often,—and many have written much,—students—men of science—religious teachers—poets, and philosophers.
We ask this question of ourselves variously circumstanced, and under various impulses. We ask it if, like Æschylus' watchman, we contemplate
"The congress of the nightly starsBright potentates, set proudly in the sky."
"The congress of the nightly starsBright potentates, set proudly in the sky."
"The congress of the nightly stars
Bright potentates, set proudly in the sky."
Or when we sail upon a sea made solemn by its vastness, dying in far distance, with no boundary except itself, as each swelling wave rises against the sky. We ask it, on some stately mountain top looking down over light and shadow,—over the rest and the motion of the landscape. More earnestly still, perhaps, while from the depth of a twilight valley we admire the sunset lingering upon inapproachable alpine snows;—rosy heights unveiling their loveliness, yet soon to be hidden till the Light of this lower world shall shine afresh amongst their clefts and pinnacles.
And who is not in earnest, as sunset and sunrise remind him how the majestic clock of Time moves on? Yonder glorious luminary has warmed with form and life countless organisms, scattered over mountain summits, in ocean depths, through wild savannahs and forests;—organisms throughout regions of earth, water, air, so remote and inaccessible thattheir wonderful excellence of beauty has never been beheld by Man's perishable eye. Knowing, as we cannot but know, how soon our own eyelids must close beneath the sun, we yearn within our soul, longing for a truer insight into the great Universe above and beyond us; and for a firmer feeling that we ourselves are an imperishable part of it. Somewhere in this Universe, must surely be contained things brighter and better than those we now possess. Else, why is it clothed so lavishly with half-revealed charms, adapted to touch our most delicate sympathies, to win us from our worse selves, and allure us on like willing captives to its loveliness? Awakened in our senses, awakened in our souls, we desire to know, to feel, and to attain;—these three impulses become our fixed and enduring aspirations.
But, how? We all remember that Undine sought a soul and found a sorrow;—a sorrow the more intolerable, because through its burden she first realized her hard-earned dower of coveted immortality. Yet, as she truly says, every creature cannot but strive after that which is naturally higher than itself.
Onesecret of progress we soon discover. What Nature can give us depends on what she can tell us. And here is a prevailing motive for the endeavour to unclose fair Nature's book.
Anotherstep in thought is early taken in our day, though the civilized world was slow in reaching it. We soon perceive that Nature's answers must catch their tone and compass from our interrogations. In numerous sciences, this axiom carries the whole theory and practice of experiment;—that grand distinction between Bacon's inductive process, and the induction of the ancient world. In other walks of inquiry, intellectual and moral, the same truth has grown up and blossomed with a ruling idea of the crucial or prerogative question: slow in being framed, and difficult often in the asking, but, when asked, certain to elicit a reply.
Athirdpostulate is also quickly apparent. Our inquiries must be subject, for utility's sake, to our power of assimilating knowledge. And thus our faculty for asking questions is governed by our faculties for apprehending answers.
Thelastand paramount requirement isforcedupon us. Beyond and over all, comes the pressure of our own need and private anxiety. There are many truths which we discern afar off, like features of a smiling land of promise; and, knowing that they must become one day the heritage of mankind, we tend towards them without haste, yet without forgetfulness, and in this temper of mind wait contentedly. But, there are some truths for which we cannot afford to wait. They concern our destinies too closely; they are too near our hearts; too influential on our lives and happiness.
The old question asked in the youth of human philosophy, is the one we all begin by asking in our first confidence and eagerness of pursuit. Ask it in what words we may, it always comes to much the same thing; and if we could answer it, we should answer all questions in one. For, though we clothe our query with various shapes, and seldom put it in the form following, its true meaning is, "what are the realities of the Universe, and what the essential ground of all we see and think?"
It is always worth a thinker's while to look this human problem more than once in the face. Suppose a faculty[88]forsuch insight granted, it must be different in kind, rather than degree, from our logic of ordinary life. It cannot proceed discursively, abstracting, generalizing, connecting, deducing. It must know—or look at its object directly, just as genius knows, images and conveys to other minds, not through a train of explanatory definition, but by kindling within them a spark of its own light. If there be such a faculty, it will work, (as Aristotle[89]says of the Supreme Intellect,) by what seems to us most like an act of touch; a figure half-shadowed out when we say we grasp or apprehend a truth; and much as St. Paul speaks, in bidding men to seek and feel after and find the Lord.
We are not all conscious of such a faculty. But if dim to some, is it certainly dim to all? Did Plato see farther than Herschel could when he burst the barriers of the sky? Did Schelling at any time behold what Hamilton pronounced invisible?[90]
Or again, if not actually ours now,—if those who have asserted it have spoken in error,—is there a hope that in the Future of Man individual or collective, he will ever grow up to it? The thought is not unknown to physicists as well as moralists. In both camps hopeful minds have conceived thepossibility. And,thenMankind will look the secret of the Universe face to face.
Meanwhile, thinking men have laid siege to the absolute Truth by aid of such powers as they commonly call into action. For centuries past, the nature of things in themselves,—and along with (or perhaps above) all other natures, the "Self" within every man has been among the most fascinating of objects pursued by human thought. Yet, how far do we really know the life throbbing in every pulse? Can we tell the secret of our own individuality? We feel it every day;—it endues us with a separate existence, distinctly several, and apart from others, and so intensely vivid to ourselves, that we seem in our own eyes like small centres of the Universe, with men and women,—nay, worlds and stars,—revolving round us.[91]Yet, strange to say, our bodies are at all times undergoing change, sufficient in a few years to eliminate their present frame, and remould a future compound of gradually assimilated elements. And it seems stranger still, that while the law of Change rules supreme in these fabrics,—(built to be continually dissolved and continually built again),—each rude mark and scar maintains its place; no old wound forgets to ache; no cicatrice even, nor superficial blemish, dies quite away. We are always changing, always being transformed; yet, to each of our bodies continues its one individual configuration; within each of our minds its self-collection, its memories, its expectations, and its individual consciousness.[t]
Weighing these inconsistencies together, shall we say that, in any proper sense, weknowour own selves? And, if not, can we expect truly to know theselfof anything? May we not travel further, and inquire whether we can conceive aself-nessof any kind,—whether the very idea is not to us absolutely inconceivable? And, when this question is answered as it must be answered, need we feel surprised if we fall short of conceiving the self-subsistent God? At what value, therefore, shall we rate sceptical arguments drawn from our failure; and resting on the fallacious consequence, that the inconceivable (or unthinkable as some prefer to call it) is likewise the impossible?[u]
That a fallacy really lurks beneath these words,—that the contrary is true, we know as a matter of fact.[92]We entertainreally no doubt whatever of our own continued sameness, and individual existence. We are quite sure that ourself-nesshas, gone on throughout the years of our natural life. How it first became clear to our inward sense, is a point confessedly disputable. Some suppose that it existed as a principle of consciousness,—a kind of primordial instinct in our minds. Others—that our internal impressions, one and all, formed a panoramic scene; impressions from without and impressions from within evenly painted on the retina of the mental eye. Time and comparison were needful to give us the true distinction. Those who think thus usually take another step; and add thatresistanceto ourself-nessfirst informs us of its being. There is resistance to a muscular sense, somewhat akin to touch, but specialized to feel the kind of impact given by things impenetrable. There is also a resistance which thwarts our desires, endeavours, and determinations. Be this as it may, we never doubt our own identity of being; we never doubt theother-nessandouter-nessof beings like ourselves, and of objects beyond number. Yet, that which makes ourselves and them, what we and they are,—ourself-ness andtheirself-ness—raises a question we cannot answer; here is, we feel, a something which overpasses our means of investigation. Men, however, do not stay to discuss such questions, or to test the origin and limits of intellectual conceptions before accepting the fact. They do not even ask whether Philosophical victory sits onthe banner of Idealism, pure or constructive; Realism materialistic or natural;—or whether it crowns any other imaginable variety of cosmological theorem. We are perfectly sure of our facts; and no array of possible difficulties whatsoever can prevail to shake our assurance.
Let us leave for the present, in its native shadows, the central point of our own self; the original centre of our earliest apparent universe. Yet, if we cannotknowthis first growing-point of our individual life, it may be useful to inquire what can we knowaboutit? can we learn, for example, how that inner vitality, once begun, is maintained and fed?—By a process of receiving into itself, (we are told), the aliment which flows through our senses. We are also told, (as appeared in the last chapter), how very requisite is a knowledge ofnaturalprocesses. Let us, then, look at this process of sense-alimentation, narrowing the problem as much as possible. We have already cut offoneend of it—the germ-point of theself-stimulated; and will now cut offanotherpiece—the assimilation of mental ideas when elaborated. We simply ask how does this food from without, getintous? The widest avenue of entrance is proverbially our sense of eyesight. Its information, (as people in general agree, from Horace down to Mr. Mill), being gathered through many definite impressions, and received from all distances, is at once the most significant, and the most commanding. The first step is clear. We see by impinging rays of light,—movements in a luminiferous ether, making images on the sensitive network of the eye; a circumstance ascertained by the same sense of sight which receives the image. From this delicate surface, begins a second series of movements;—they take place this time in an organized nerve-material, and are carried, like telegraph-currents, to the Sensory. Arrived there, we may next suppose that they excite some new motions, or corpuscular changes. Do we know—canwe know any more? Is the grammar or dictionary written which translates them into the language of the mind; or teaches us how we have, since our infancy, worked a perpetual miracle of speech respecting each of them? The eye, as an optical instrument,[v]is a marvel of science displayed; the eye as an instrument of intelligence, especially of human intelligence, is a marvel of inscrutable mystery.
The mysteries of every-day life are the last things dreamed of in every-day philosophy. When we wake up to their existence, it is astonishing to find how continually, without being able to explain things, we can feel, and know them;—know them that is in the sense of acting intelligently (without theorizing) upon them.
The example we have taken, teaches us several good and important lessons. There is in it much we can understand; much that we cannot understand; and a twilight territory between the intelligible and the non-intelligible. All three are, of course, mixed together when we speak of sight,—in itself, a matter of every-day experience. So far as the mechanical construction of an optical chamber goes, everything seems obvious. We can, likewise, perceive how well contrived is the apparatus for washing and wiping the outside transparent surface. Also, the value of its arched hedge against irritants dropping upon the eyeball from above; and of the arrangements for altering both axis and focus instantaneously. But what does this instrument enable us to see?Notthe rays of light themselves,—only objects which they illuminate. The space traversed by rays from all suns and all stars, remains itself unseen. The ether which fills space is invisible,—yet its motions make the light of the world.[93]Then, too, the nervous screen on which these ray movements are received, is not sensitive to all transmitted undulations. Red excites the optic nerve by striking it with four hundred and seventy-fourmillions of millionsof wave-impacts in a single second. Violet strikes it in the same time with six hundred and ninety-ninemillions of millionsof impulses.[94]These two colours are the extremes of the light octave. In an octave of sound, the highest note vibrates twice as quickly as the lowest. So too, the shortest wave of violet is half the length of the longest red wave, and its motion is twice as rapid. But the curious point is that the human ear receives eleven octaves in the scale of sound;[95]—the human eye has a range over only one octave in the scale of light.
Our remarks have carried us over the borders of the twilight territory,—a circumstance we may ascertain byputting into words what we think we know, and our reasons for thinking that we know it. If the eye be in focus, (but not otherwise), a line of light—that is to say moving imponderable matter of extreme tenuity—so passes through its transparent liquids as to strike a sensitive spot, and there produce what is called an image. We apprehend in our minds this image-producing function as a relation between light and the effect realized. A relation definite and exact,—in scientific language a "constant"; which we can formulate into optical laws, and thus express with useful nicety. Taking advantage of the laws thus obtained, and employing that light-power which everywhere blesses our world, we reproduce thelike, image upon a screen. Its likeness we gather from comparison, by looking into an eye from without. Both images, thus seen by us, are in point of fact similar sensations.
A philosophic reader may at once perceive what the Idealist will infer respecting this act of comparison. Neither image—on retina or on screen—exists apart from the eye. So far as we know, if there were no eyes there would be no images; and some writers (e.g., Schleiden) have positively affirmed that without eyes all would be, not only to us, butin itself, darkness;—the world absolutely void of Light. But the truth may be summed in a sentence. Light is not for the eye in the same sense that the eye is for light. Light is for other things besides. It exerts its activity on life, animal and vegetable;—on inorganic substances;—and in other ways likewise.—Going no further than our screen, we can so manage matters as to engrave and otherwise fix the image thrown upon it;—in other words our moving line of imponderable matter will produce further effects, chemical and mechanical, visible and palpable.
Proceeding to a cross-examination of the knowledge with which we have credited ourselves, our next business is to try whether we can verify the objectivity of our optical image. Now it impresses sight in two respects,—as superficial form—and as colour. The family of forms is, we are aware widely connected. Sound evokes them. Draw a violin bow across a string stretched over finely silted sand, and the differentnotes will be correlated by a diversity of shapes,[96]into which the sand will arrange itself. Therefore, we ought to find means of verifying Form without much difficulty. Indeed we do so every day satisfactorily; our hands are perpetually demonstrating the general accuracy of our eyes, and even those delicate instruments our finger-ends, do not always add much to the information sight has given us.
But about colour? Distinct colour-waves have (as we said before) distinct velocities, and are therefore objectively distinguished even in the inorganic universe. They also act differently upon the growth of animals and plants,—and other distinctions might be added. Thesensationis, however, our point,—the special thing called colour both by careful speakers and in child parlance,—what do we really know about this? Little indeed except as an impression received by sight. The man born in complete blindness taking a piece of red cloth to examine, described the fabric minutely; but, when asked if he could say anything about its redness, likened that "hue angry and brave" to the sound of a trumpet. A simile most conclusive,—suggested probably by his having often heard of certain "scarlet-coated gentry";—and proving beyond doubt that colour is non-existent in the sensory of a person affected from birth by a deep-seated lesion. To one less thoroughly blind, spectra are possible, and red light may be produced under pressure. It thus appears, that colour must be perceived by a nervoussubstratum, called the rod and cone layer; and hence we explain our power of distinctly seeing the blood-vessels of the retina lying immediately before that structure.[97]
These curiosities, of vision shew that our powers of verifyingshape are superior to our powers of verifying colour;[98]add, too, that the latter sensation, (as an idealist might maintain,) is known to be sometimes unreal, since it occurs without a coloured object. We can produce it, for instance, by gazing at the sun—a phenomenon mentioned by Aristotle. But then,this ideal sense-affection ranges with a variety of others, which taken together constitute a very much wider law. Not to mention many superinduced mental states, we see light under the influence of a touch or blow,—of electricity,—of chemicals, such as narcotic medicines, which attack the nervous system. We hear sound under like appliances stimulating the auditory nerve. And the whole of these affections are to be explained by another Aristotelian doctrine, extended and pushed to its consequences. Special senses have their own proper faculties, and when called into action each exerts its power within its special province. Had Aristotle dissected out nerve-fibres, he might have discovered the larger empire of specialty now known to our anatomists.[99]
Idealism easily widens its doubt, to correspond with the dimensions of the wider nervous law. Does not an aptitude for special impressions, so stringently determined as to translate the antecedent "blow" into the consequent, "light" or "sound," disqualify our senses for giving evidence respecting supposed facts of the outer world? As for the "distinctive impressibility of the eye," as Mr. Bain[100]describes colour, it neednot be held real except for our own sensorium,[w]and if colour be a questionable reality, other alleged realities become questionable too. The world we live in, may be a totally differentworld from what we are taught, generation after generation, to believe it. Who can lay down the limits of what our minds create for themselves outside us?[101]The mental disease of the madman causes his eye to see that which is not. Guilt and sickness fill bedchambers with unreal spectres. Putting disease aside, and taking the case of healthy eye and healthy mind, it is confessedly difficult to define the exact province of each. A boy couched by Cheselden[102]saw all things in one plane; there was no perspective, and objects in the room seemed to touch his eyeballs. The mind creates perspective, how much then may it not create? The mind also refuses to surrender its own associations at the bidding of optical laws. Mr, Wheatstone's ingenious instrument called the Pseudoscope, brings into play laws which reverse the impressions of solidity and hollowness. A person looking through it steadily at the face of a statue sees a hollow mask. The convexity of feature is gone, and a concave set of features (representing the bust reversed) is perceived in its stead. But, let the same person gaze through his pseudoscope ever so long at the face of a human being, and he will look for a like reversal in vain. The flesh and blood features refuse to change;—in other words, the mind refuses to yield itslong-accustomedimpression.[103]If these things and others like them are fairly considered, what becomes of our readings in the unclosed book of Nature? The nature we see is our own thought reflected back again. Nature's answers take not only tone and compass, but meaning and utterance from our own interrogations. We think that we are assimilating knowledge, when we are actually engaged in manufacturing aliments to suit our own intellectual digestions. The most inward of all things,—our essentialself,—at once retired into shadow when we pursued it; and now, in trying to show howselfis fed by substance from without, we have learned to suspect that all its food is unsubstantial.[x]
We may henceforth consider ourselves face to face withSphinx; and it is well to take the true measure of her lineaments. If the above reasoning be sound, to know, is to make a mirror and reflect ourselves back from it. To verify, is to put ourselves in new postures before our infallible mirror. Each fresh item of induction, is a freshly reflected phantom. At all events, the contrary position will never be established. Ignorant as we are, respecting the true centre of our mental firmament, we must necessarily be always more ignorant respecting allpossibilitieswhich seemingly outlie its glowing horizon. No one who rationally weighs the worth of a fact, or whodecomposes it into its elementary constituents, will ever be absurd enough to imagine that he can disprove the ideal theory by proving the truth of its opposite.
The strongest strain of Idealism comes upon thelastsentence. Some years ago, English philosophers had agreed in the conclusion that all debates must for the future be settled by an appeal to facts. Could there be a more happily chosen ground for arbitration?—or one better suited to the calibre of everybody concerning whose business-like reflections we might say, with King Henry,—