CHAPTER XVI.
POSSIBILITY OF OTHER SENSES
91. Lamennais writes: "Who can say that a sixth sense would not disturb the harmony of the others by a contrary impression? On what foundation could he deny it? If we suppose other senses different from those which nature gave us, might not our sensations and our ideas be different? Perhaps a slight modification in our organs would be sufficient to ruin our whole science. Perhaps there are beings so organized that their sensations are wholly opposed to ours, and what is true for us is false for them, and reciprocally. For, if we examine the matter closely, what necessary connection is there between our sensations and the reality? And if there were such a connection, how could the senses make it known to us?"38
The questions which these words raise are of the highest importance and merit a serious examination.
92. Is there any intrinsical impossibility of an organization different from ours, and an order of sensations different from those which we experience? It seems not; and if this impossibility exists, it is unknown to man.
Whatever opinion we adopt as to the manner in which external objects act upon the soul by means of the organs of the body, there is no necessary relation, nor even analogy, between the object and the effect which it produces in us.
A body receives upon its surface rays of the fluid which we call light, these rays are reflected upon the retina, which is another surface in communication with the brain. So far all is well, and easily understood. There is a fluid which moves, goes from one surface to another, and may cause this or that purely physical effect on the cerebral matter; but what connection is there between this and the impression of a distinct order which we call seeing, an impression which is neither the fluid nor the motion, but an affection of which the living and thinking being, the me is intimately conscious?
If, instead of the luminous fluid and its mechanism, we suppose another, as, for example, the air which vibrates upon the tympanum, what essential reason is there why this should not produce a sensation similar to that of sight? It must be confessed that it is impossible to assign an essential reason. To one who has no idea of our present organization, both phenomena are equally incomprehensible.
93. What has been said of sight and hearing may be applied to the other senses. In all there is a bodily organ affected by a body; we see the surfaces placed one before or under the other, we see motions of one kind or another; but how can we pass over the immense distance which separates these physical phenomena from the phenomenon of sensation? For my part, I see no way to do it; this point is a barrier to the human intellect; all appearances indicate that there is no connection between these two orders of phenomena except what the will of the Creator has freely established; if there is any necessary connection, this necessity is a secret to man. Examine the textures which receive the impression of the objects, the material substance which composes the nervous system which is the organ of sensations, and say what relation you can find between the physical phenomena of this matter and the wonderful harmony of sensible phenomena.
94. Still greater will be the difficulty if you consider that, although protected from any injury, the organs cease to produce sensations from the moment they are deprived of communication with the substance of the brain. The phenomena of light are produced in the cavity of the skull amid the most profound darkness; and all the wonderful magic of sensations by which the magnificent spectacle of the universe is presented to our mind, which plunges the soul into raptures at the sound of music, and which produces such varied and delightful sensations of taste and odors, all arises in the brain, a whitish, rude, and unformed substance, from the appearance of which no one could imagine it destined to such noble functions.
95. Why is it that when the nerve A, in communication with the brain is affected, we experience the sensation which we call seeing, or if the nerve B is affected, the sensation which we call hearing, and so of the other senses? There may be a reason, but, at least, we do not know it; and it is probably no other than the free will of the Creator.
Here, it is true, philosophy confesses its weakness, but, at the same time, it shows its power; for it sees the immense distance which separates these phenomena, between which there can be no point of communication but what is established by the Almighty. When there are second causes, it is the merit of philosophy to discover them; but when there are none, its merit is in rising to the first cause. A confession of its ignorance is sometimes a more sublime act of reason than the impotent effort of an unbounded pride. If the perception of profound truths exalts the intellect, is not the intellect exalted in perceiving its own ignorance, which is sometimes a profound truth?
96. The existence of another sense is, then, possible; at least, we see no impossibility of it. If the deaf man who has no idea of sound, and the blind man who knows not what color is, would be foolish to deny the possibility of those sensations of which they are deprived, can we, with any more show of reason, assert the impossibility of an order of sensations different from what we possess? If we examine the system of sensations by the light of reason, we can discover no essential dependence between the sensations and their respective organs, nor between the organs and the objects and circumstances by which they are affected. Why does the impression of the light upon my eyes cause in me a particular sensation, which cannot result from the same impression on a different part of my body? Why may not the brain receive the same impression in various forms? Why must this fluid which we call light, and no other, produce the impression? Why may not this same sensation of seeing proceed equally from other affections of the brain? A violent blow on the head produces the sensation of many luminous points, whence the common expression of "seeing stars by daylight." We must confess that philosophy knows nothing of these secrets, that as yet it has not been able to penetrate them, and it can give no answer to these questions. It sees an order of facts, but no necessary connection between them, or rather, judging from its ideas of mind and body, every thing induces it to believe that these phenomena in our life depend solely on the will of our Creator.
97. If an entirely new order of sensations is possible, there may be beings with six or seven senses. The imagination cannot conceive their nature; but reason sees in them no impossibility.
CHAPTER XVII.
EXISTENCE OF NEW SENSES
98. Is it certain that we have only five ways of sensation? I have some doubts on this point. In order to present them with the greatest clearness, and solve the questions which they raise, it is well to settle the meaning of the terms.
What is sensation? In the ordinary acceptation of the word, it is the perception of the impression transmitted to us by one of the organs of the five senses. Thus understood it is clearly limited to the action of the organs, but if considered as expressing a certain class of animal phenomena, it is the experiencing of any affection produced by an impression of the organism. Even in common use the word sensation in its broadest signification is not restricted to the impressions of the five senses, and although we make a great difference between sentiment and sensation; still we are often forced to confound them, and to use the word sensation to express things which have nothing whatever to do with the five senses. Thus we say: "The news made a great sensation;" "I cannot resist the force of such strong sensations," etc., in which cases it is evident that there is no reference to seeing, hearing, smelling, tasting, or touching, but to a different order of affections of the soul.
99. I said we were forced to use the word in the broader meaning; it is the truth which forces us. For, to the eyes of philosophy, the phenomenon of sensation consists in the production in the soul of a particular affection determined by an impression on an organ; and of whatever order this affection may be, and whatever organ may be affected, the animal phenomenon is substantially the same. The difference is in the class of affections and of the organ which is their medium, the essence of the phenomenon does not change. And if by sensations we understand such distinct orders of affections as those of sight and of touch, why may we not include other impressions caused by any other organ, whatever that organ may be?
100. Whatever use we may make of the word sensation, it is certain that we experience many affections caused by organic impressions, besides those of the five senses. What are passions but affections of the soul, springing from organic impressions? Does not the mere presence of an object often excite love, anger, pity, joy, grief, and many other sentiments of the soul?
You may say there is an essential difference between the impressions of the senses and those of the passions, that the former are independent of all previous idea and reflection, which the latter more or less presuppose. Thus, when an object is present to our open eyes, we cannot but see it and always in the same manner; and yet this object will excite in us at one time one passion, at another time another, and sometimes none; and almost always with great difference in the degree of its intensity. Moreover it is not only the mere presence of the object which causes an affection, but certain conditions are necessary, for example; the remembrance of a benefit or of an injury, etc., from which it is easy to see that there is an essential difference between the two classes of impressions.
101. If we reflect well upon this objection we shall find that though it is specious and under many aspects true, it contradicts nothing which I have asserted. I did not deny that the new impressions were subject to very different conditions from those that govern the five senses; but on the contrary I have all along supposed a difference not only in the class of impressions and the diversity of the organ, but also in the manner in which the organ is affected, and the circumstances in which the sensation is produced in the soul. I only contended that the animal phenomenon was substantially the same, that we find in it the three things which constitute its nature; a corporeal object; an organ affected by this object; and an impression produced in the soul. Because this impression cannot exist without the aid of this or that idea, this or that recollection, it does not follow that the phenomenon does not exist, or that it is not the same; it is merely to impose a new condition, and nothing more.
102. But there is no necessity of admitting that some previous idea or reflection is requisite in order that the sight of the object may produce certain impressions in the soul; – daily experience proves the contrary. How is it that the presence of an object charms in an instant a tender and perhaps innocent heart? Whence then arises that sudden fascination which is preceded by no idea, accompanied by no affection, and is scarce voluntary? Not from the thought of gross enjoyments; for perhaps he of whom I speak knows not their existence until he experiences this emotion; he feels for the first time in his breast a trouble unknown before. We must therefore recur to an organic affection similar to that which we find in the other senses. Certain conditions of age and temperament may be requisite, one object may have been necessary, among a thousand, in particular circumstances, of which the soul can give no account to itself though affected by them; yet it is still true that there is an external object, an affection of the organism, and an impression in the soul, all connected together by a mysterious, but undeniable bond.
It is easy to discover a series of strong impressions in the phenomena relating to reproduction; but although they presuppose the action of some one of the five senses, they nevertheless belong to a different order. No physiological studies are necessary to prove that these affections depend on the organization, and that they are greatly influenced by age, health, temperament, food, climate, and the seasons.
103. There is a difference between sentiments and sensations which, though it does not change the fact physiologically and psychologically considered, still greatly modifies it in its intellectual and moral relations. The passions are commonly excited by an animate and sensible object, whence it would seem that there is more communication between mind and mind, between soul and soul, than there is between one body and another. The sad and mournful appearance not only of a man, but even of an animal, immediately excites in our breast the sentiment of compassion, because it expresses the suffering of a living being. This only proves that nature has mysterious ways by which it transmits to us the knowledge of hidden things; but this transmission is made by the medium of a body which affects in some way our organic constitution. There is here, if you please, a more admirable, more penetrating, and more spiritual a magic than that of the senses alone; but the difference is in the degree, not in the nature of the phenomena.
It is certain that living beings, and those of the same species in particular, are in a constant communication which mutually excites their affections, and that these affections frequently suppose a mysterious correspondence with unknown agencies. Physical nature is full of fluids whose qualities are daily becoming known through scientific observation. The phenomena of electricity and galvanism have revealed secrets of which we had no suspicion before. Who can tell by what means the functions of this vast and complicated system of animal life, spread over the universe, are performed? It is probable that there are profound secrets in the correspondence and relation of organisms and in the way in which they influence one another yet to be discovered; perhaps they will remain forever veiled to the eyes of mortality.
104. Is it true that sensible beings can alone excite the passions? or have not inanimate causes repeatedly affected our organs? Why are we sometimes joyful and sometimes sad, at some times peaceful and at others irritable, when we have had no communication with any living being? It is clear that this depends on the affections of our organism, and has no relation to the state of other sensible beings.
105. Therefore, besides the impressions caused by the five senses, there are others which proceed from purely corporeal and inanimate objects. Besides the phenomena of ordinary sensations, there are others which differ from them only in the kind of impression and the organ affected; and there is no more difference between these sensations and the former than there is between the impressions of one and those of another of the five senses. Therefore it is not correct to say that there are only five kinds of sensation.
CHAPTER XVIII.
SOLUTION OF LAMENNAIS' OBJECTION
106. From the preceding observations we shall now deduce an important consequence, – the solution of the difficulty presented by Lamennais. The existence of new senses would involve new sensations, it is true; but they would not disturb the harmony of those we already have. We have shown that bodies affect our organs in a different manner, and produce impressions different from those of the five senses; but this does not disturb the agreement of our sensations, nor change our ideas. Consequently, the supposition of Lamennais would not involve the disorder which he suspects.
107. Sensations in themselves are mere affections of the soul, and have no external object which corresponds to them except the existence and extension of bodies. Therefore a new order of sensations would only be a new order of affections, which would in nowise alter our ideas.
From what we have hitherto said, it is easy to see that the supposition of Lamennais is already realized; for there are sensations different from those of the five senses; therefore this supposition does not contradict the nature and order of our ideas, nor the certainty of our knowledge.
A musical instrument beautifully fashioned has charms for the ear, the eye, and the touch, none of these impressions destroys the other; if we suppose it placed in new relations with our organs, so as to produce in the soul new impressions, why is it impossible that they should accord? Does the melody of its sound cease because our soul experiences new affections whose nature has no connection with it? Certainly not. Why then fear the overthrow of our knowledge by the introduction of a new order of sensations? Why give such importance to a supposition, the effects of which we can very well calculate, and which, if we examine the phenomena of our present sensations, we find already realized?
108. It is true that we know of no other means of placing ourselves in contact with external objects than the five senses; but it is equally true, that this contact existing, the impressions in the soul correspond mysteriously to the external objects; so that, while we observe the sensations by which the communication is established, it is still impossible for us to explain them.
Let us examine the magical effects of music. They are of two orders; the purely auditive, and the intellectual or moral. The first stop at the ear, the second pass to the brain and to the heart; and one may be admirably organized for the former, yet unable to appreciate the latter. Two persons listen to a sonata, both hear the material music, but the intellectual and moral effects are not the same on both. Both perceive the least defect in the time or in the instrument, both admire the art of the composer, both are charmed; but while the heart of one is unmoved, the brain and the heart of the other are bounding with delight, the power of his fancy is multiplied, thoughts and images crowd upon his mind, as though he had caught inspiration from the magic notes of the music. His heart is transported with tenderness, melancholy, hatred, love, anger, generosity, and courage. He is under a magical influence which, moves him in spite of himself; the vibrations of a chord have raised in his heart a mysterious tempest which the might of reason can hardly quiet.
109. From this we must conclude, that besides the ordinary relations between objects and the organs of the senses, there are other relations still more intimate and more delicate between these objects and our organic system, and that these latter are as certain as the former. In them there is greater variety of individuals, and the conditions necessary to produce determinate results are less known, but there can be no doubt of their existence, and this in the eyes of sound philosophy is sufficient to dissipate those absurd suppositions which would pretend to undermine the edifice of our knowledge.
110. Thus, then, the objection is answered, which says: "If we had another sense, what would it tell us?" Nothing which would destroy the certainty of our knowledge, or the nature and order of our ideas. The only new result would be one more added to the many ways in which objects now affect us. The same thing would happen to us as to a man who after being deprived of the sense of smell, should suddenly regain it: he would have one sensation more; the same thing would happen to us as to a man who experiences a new sentiment which he had not known before: he has one affection more. New impressions have their own rank, neither interfering with, nor changing those which previously existed.
BOOK THIRD.
EXTENSION AND SPACE
CHAPTER I.
EXTENSION INSEPARABLE FROM THE IDEA OF BODY
1. Having seen that among the objects of our sensations, extension alone has any external existence for us as any thing more than a principle of causality, let us now try to understand what extension is.
The idea of extension seems to be inseparable from that of body; at least, I am unable to conceive a body without extension. Take away extension, and the parts disappear, and with them all that has relation with our senses; there is no longer an object, or, if the object remains, it is something altogether different from what is contained in the idea of body. Imagine an apple, for instance, from which you suddenly take away extension. What will remain of it?
I am not now going to examine whether Descartes is right when he says, that the essence of body consists in extension; all that I here assert is that a body cannot be conceived without extension. I do not affirm the identity of two things, but only the inseparability of two ideas in our mind. It is not an opinion, but a fact asserted by consciousness, which is now under discussion.
Abstracting extension, I can conceive, it is true, a substance, or, to speak more generally, a being; but, then, there is no idea of body, unless we confound this idea with, that of substance or of being, in general.
2. All our notions of bodies are obtained through the senses, but without extension no sensation is possible; for without it there can be no color, no sound, no touch, no smell, and no taste; therefore, without extension there remains only something of which we have no idea, a vague notion which cannot enable us to distinguish one object from another, a pure abstraction, and nothing more.
3. To solve the difficulties which attend the separation of the two ideas of extension and of body, it is necessary to determine the essence of body. When we can distinguish the essence of a body from its extension, the difficulty will be overcome, but not until then.
4. In order to understand the reason of this inseparability, it is necessary to remember what was said before, that extension is the basis of all other sensations; it is the substratum which is confounded with none, depends on none of them in particular, yet is an indispensable condition of them all.
I look at an apple, and examine the mutual relations of the sensations which it produces.
It is evident that though I abstract the smell, I do not thereby destroy any of the other sensations which it causes. Though it lose its odor, it is still extended, colored, it has a taste, and may produce a sound. I may also, in like manner, abstract its taste, its color, and all that relates to the sight, but I have still an object which is tangible, and consequently extended, figured, and possessed of all its other properties which affect the touch.
If instead of abstracting what relates to the sight, I abstract what belongs immediately to the touch, I may do this without destroying the other sensations; for I can still see the apple, its extension, form, and color.
I may even go farther, and strip the apple of all its sensible qualities, of its taste, smell, color, hardness, and whatever the senses can perceive, still there remains extension, not indeed sensible, but conceivable. Extension exists abstracted from its visibility, since it exists for the blind man: abstracted from its tangibility, since it exists for the sight; abstracted from odor, taste, and sound, since it exists for those who are deprived of these sensations, so long as they have sight or touch.
5. Here a difficulty arises. There seems to be a mistake in what we have said of the existence of extension abstracted from other sensations; for, although in making this abstraction we conceive ourselves to be deprived of these sensations, still we retain the imagination of them; thus, when I strip the apple of all light and color, it is still extended; but that is because I still imagine a color, or, if I make a strong effort to destroy the color, it appears to me like a black object, on a ground of greater or less darkness, distinct from the apple. Does not this prove that there is an illusion in such abstractions, and that there is no complete abstraction, since the reality which we abstract is succeeded by the imagination of the same qualities, or of others which supply their place, so as to make the extension perceptible?
This objection is specious, and it would be difficult to give a satisfactory answer if the existence of men deprived of sight did not instantly dissipate it. No such imagination is possible in the case of a blind man, for him there is no color, no shade, no light, no darkness, nor anything which relates to sight, and still he conceives extension.
6. But at least, some one will answer, it must be confessed that the idea of extension is necessarily dependent on the sensations of touch; blind men also possess this sense, and by it they acquire the idea of extension. Therefore the idea of extension is inseparable from the sensations of touch. This argument is no better than the other; for, although we may acquire the idea of extension by the sense of touch, and this sense is all that is required to produce it, it is not true that this idea can only be acquired by touch. I have already proved that sight is sufficient of itself alone to produce the idea of the three dimensions which constitute a solid or extension in its full complement. But here I do not need the idea of a solid, that of a surface is sufficient; the extension of a surface is inseparable from sight. There is no sight without color, or light of some kind or other, and this cannot even be imagined without a surface.
I have another argument. Geometricians, doubtless, conceive extension, and yet they abstract all its relations to sight or touch; therefore, there is no necessary connection between them.
In any object submitted to the sight, what quality relating to the touch is necessary in order to produce the idea of extension? If we examine it closely, we shall find that there is none. Let us take a liquid; is its fluidity the necessary quality? No; for when congealed extension remains. Is it heat or cold? No; for without destroying its extension we may change its temperature as much as we please, no alteration is perceptible. Whatever quality relative to touch we may take, we shall find that it may be varied, modified, or entirely destroyed, without visibly affecting the extension.
It often happens that we have a clear and definite idea of the extension of an object without knowing any thing of its qualities in relation to touch. I see an object at a distance, I distinguish its color and its form, but I know not of what material it is, whether it is of marble, or wood, or wax, nor whether this material is hard or soft, moist or dry, warm or cold. I do not even know if it is tangible, as in the case of figures formed by vapors which are imperceptible to the touch.
7. Without extension there can be neither sight, nor touch, nor any other sensation. As to taste, it is clear that it requires touch, and cannot exist without it. Our assertion is less clear with regard to sound and smell; for, although we cannot separate these sensations from the idea of extension as they always involve this idea in one way or another, we do not know how it would be with a man who was deprived of all the other senses, and retained only those of smelling and hearing. But without speculating on this hypothesis, it is enough to know:
I. That nothing which is not extended can act upon our organs, unless by means wholly unknown to us, and which would give no idea of what we understand by body.
II. That even supposing the sensations of smelling and hearing to be possible without the idea of extension, they would in that case be only simple phenomena of our being, and would not place us in communication with the external world, as we now perceive it; because, if we should not know that they proceeded from another cause, we could have no more consciousness of them than that which we have of the me; and if we should know it, this cause would be represented to us only as an agent influencing us, and not by any means as a being having any thing similar to what we understand by body.
III. That in such a case we should have no idea of our own organization, nor of the universe; for it is clear that every thing being reduced to mere internal phenomena, and their relation to the agents producing them, and the idea of extension wanting, neither the universe nor our own body would be to us what they now are. What would the universe, – what would our body be without extension?
IV. That for the present we limit ourselves to the demonstration of the dependence which in the present system, of things, all sensations have in relation to extension; and this demonstration holds good, even though we suppose the man who possesses only the sense of smelling or that of hearing not to form any idea of extension, and not to need it in order to experience its sensations.
V. That even on this supposition, the proposition before established, that the idea of extension is independent of the other sensations, still remains unassailed.
VI. That the truth which we are principally endeavoring to demonstrate, that for us the idea of extension is inseparable from that of body, also stands firm.
8. This inseparability is so certain, that theologians explaining the august mystery of the Eucharist, distinguish in the extension of bodies the relations of the parts to each other, and their relation to place, in ordine ad se, et in ordine ad locum; and they say that the sacred body of our Lord Jesus Christ is in this august Sacrament, by extension in ordine ad se, though not by extension in ordine ad locum. This proves that the theologians saw that it is not possible for man to lose all idea of extension, without at the same time losing all idea of body; and thus they invented this ingenious distinction, of which I shall speak at greater length in another place.