The Light Course
31 December 1919, Stuttgart
My dear Friends,
The way of speaking about sound and tone which you will find in the customary description of modern Physics may be said to date back to the 15th century at the earliest. By such examples you will most readily confirm what I so often speak of more generally in Spiritual Science. Namely, before that turning-point in time, man's whole way of thinking was very different from what it then became.
The way we speak of the phenomena of sound and tone in the scholastic system of modern Physics came about only gradually. What first caught their attention was the velocity with which sound is propagated. To a first approximation it is not difficult to find what may be interpreted as the speed of propagation of sound. If a gun is fired at some distance from you, you see the flash of light in the distance and hear the report some time later, just as you hear the thunder after you see the lightning. If you neglect that there is such a thing as a velocity of light, you may then call the time that elapses between your perception of the impression of light and your perception of the sound, the time the sound has taken to go the corresponding distance. So you can calculate how quickly the sound advances in air — how far it goes, say, in a second — and you get something like a “velocity of propagation of sound”.
This was one of the earliest things to which men became attentive in this domain. They also became attentive to the so-called phenomena of resonance — sympathetic vibration. Leonardo da Vinci was among the first. If for example you twang a violin-string or the like, and another string attuned to it — or even quite a different object that happens to be so attuned — is there in the same room, the other will begin vibrating too. The Jesuits especially took up the study of these things. In the 17th century much was done for the science of sound or tone by the Jesuit Mersenne, who made important researches on what is called the ‘pitch’ of a musical note. A note contains three elements. It has first a certain intensity; secondly a certain pitch; thirdly a certain quality or colouring of sound. The problem is to ascertain what corresponds to the pitch, — to ascertain this from the point of view which, as I said, has gradually been adopted in modern time, — adopted most of all, perhaps, in this branch of Science. I have already drawn your attention to the fact which can indeed easily be ascertained. Whenever we perceive a sound or a musical note, there is always some oscillatory phenomenon that underlies it — or, shall we rather say, accompanies, runs parallel to it. The usual experiments can easily be reproduced, to demonstrate this oscillatory character of air or other bodies. Here is a tuning-fork with a point attached, which as it moves can make a mark in the layer of soot, deposited on this glass plate. We need not actually do all these experiments, but if we did strike the tuning-fork to begin with, the picture on the glass plate would reveal that this tuning-fork is executing regular movements. These forms of movement are naturally conveyed to the air and we may therefore say that when we hear any sounding body the air between it and us is in movement. Indeed we bring the air itself directly into movement in the instruments called pipes.
Now scientists have gradually discovered what kind of movement it is. It takes place in ‘longitudinal’ waves, as they are called. This too can be directly demonstrated. We kindle a note in this metallic tube, which we connect with another tube full of air, so that the movements of the metallic tube are communicated to this air. If we then put a very light and mobile dust into the tube that is filled with air, the mobility of the tiny spheres of dust enables us to recognize that the sound is propagated just in this way; first there arises a condensation, a densifying of the air; this will beat back again however as soon as the body oscillates the other way. So there arises a thinning-out, a dilution of the air. Then at the next forward beat of the metal the original condensation goes forward; so then dilutions and condensations alternate. We can thus prove by direct experiment that we are dealing with dilutions and condensations of the air. We really need not do all these experiments; they are at hand, if I may say so. What you can get from the text-books is not what I am here to shew.
It is significant indeed, how much was done for these branches of Physics, especially at the beginning of modern time, either by the Jesuits themselves, or else was set on foot by them through all their social connections. Now from this side there was always the strong tendency, above all things, not to enter spiritually into the processes of Nature, — not to penetrate to the spiritual in Nature. The spiritual should be reserved for the religious life. Among the Jesuits it was always looked upon as dangerous to apply to the phenomena of Nature spiritual forms of thought such as we have grown accustomed to through Goethe. They wanted to study Nature in purely materialistic ways, — not to approach Nature with the Spirit. In some respects therefore, the Jesuits were among the first to cultivate the materialistic ideas which are so prevalent today. Historically it is of course well-known, but people fail to reflect that this whole way of thinking, applied to Physics nowadays, is fundamentally a product of the said tendency, characteristically Roman-Catholic as indeed it is.
One of the main things we now have to discover is what happens when we perceive notes of different pitch. How do the external phenomena of vibration, which accompany the note, differ with respect to notes of different pitch? The answer can be shewn by such experiments as we are now about to demonstrate. You see this disc with its rows of holes. We can rotate it rapidly. Herr Stockmeyer will be so kind as to direct a stream of air on to the moving disc. (He did.) You can at once distinguish the different pitch of the two notes. How then did it arise? Nearer the centre of the disc are fewer holes, — 40 in fact. When Herr Stockmeyer blew the stream of air on to here, every time it came upon a hole it went through, then in the intervening space it could not get through, then again it could, and so on. Again and again, by the quick motion of the disc, the next hole came where the last had been, and there arose as many beats as there were holes arriving at the place where the stream of air was going. Thus on the inner circle we got 40 beats, but on the outer we got 80 in the same period of time. The beats bring about the wave, the oscillations or vibrations. Thus in the same period of time we have 80 beats, 80 air-waves in the one case and 40 in the other. The note that arises when we have 80 oscillations is twice as high as the note that arises when we have 40. Sundry experiments of this kind shew how the pitch of the note is connected with the number of vibrations arising in the medium in which the sound is propagated.
Please take together what I have just been saying and what was said once before; it will then lead you to the following reflection. A single oscillation of condensation and attenuation gives, as regards the distance it has gone through, what we call the wave-length. If n such waves arise in a second and the length of each wave is s, the whole wave-movement must be advancing n times s in a second. The path, the distance therefore, through which the whole wave-movement advances in a second, is n times s. Now please recall what I said in an earlier lecture. I said that we must carefully distinguish all that is “phoronomical” on the one hand, and on the other hand all that which we do not merely think out in our own inner life of thought but which consists of outer realities. In effect, I said, outward realities can never be merely spatial, or arithmetical (able to be numbered and calculated), nor can they be mere displacements. Velocities on the other hand are outward realities, — they always are. And of course this remains so when we come to sound or tone. Neither the s nor the n can be experienced as an external reality, for the s is merely spatial while the n is a mere number. What is real is inherent in the velocity. The velocity contains the real being, the real entity which we are here describing as ‘sound’ or ‘tone’. If I now divide the velocity into two abstractions, in these abstractions I have no realities; I only have what is abstracted, separated out and divided from it. Such are the wave-lengths — the spatial magnitudes — and also the number n. If on the other hand I want to look at the reality of the sound — at what is real in the world outside myself, — then I must concentrate upon the inner faculty of the sound to have velocity. This then will lead me to a qualitative study of the sound, whereas the way of studying it which we have grown accustomed to in modern Physics is merely quantitative. In the theory of sound, in acoustics especially, we see how modern Physics is always prone to insert what can be stated and recorded in these extraneous, quantitative, spatial and temporal, kinematical and arithmetical forms, in place of the qualitative reality which finds expression simply and solely in a certain faculty of speed, or of velocity.
Today however, people no longer even notice how they sail off into materialistic channels even in the theory of sound. It is so evident, they may well argue, that the sound as such is not there outside us; outside us are only the oscillations. Could anything be clearer? — so they may well contend. There are the waves of condensation and attenuation. Then, when my ear is in the act of “hearing”, what is really there outside me are these condensations and attenuations; that unknown something within me (which the physicist of course need not go into, — it is not his department) therefore transforms the waves into subjective experiences, — transforms the vibrations of the vibrating bodies into the quality that is the ‘sound’ or ‘tone’. In all manner of variations you will find ever the same proposition. Outside us are the vibrations; in us are the effects of the vibrations — effects that are merely subjective. In course of time it has become part of their very flesh and bone, till such results emerge as you find quoted from Robert Hamerling for instance in my Riddles of Philosophy. Having absorbed and accepted the teachings of Physics, Hamerling says at the very outset: What we experience as the report of a gun, is, in the world outside us, no more nor less than a certain violent disturbance of the air. And from this premise Hamerling continues: Whoever does not believe that the sensory impression he experiences is only there in himself while in the world outside him is simply vibrating air or vibrating ether, — let him put down the book which Hamerling is writing; such books are not for him. Robert Hamerling even goes on to say: Whoever thinks that the picture which he obtains of a horse corresponds to an outward reality, understands nothing at all and had better close the book.
Such things, dear Friends, for once deserve to be followed to their logical conclusion. What would become of it if I treated you, who are now sitting here, according to this way of thinking (I do not say method, but way-of-thinking) which physicists have grown accustomed to apply to the phenomena of sound and light? This surely would be the outcome: You, all of you, now sitting here before me, — I only have you here before me through my own impressions, which (if this way of thought be true) are altogether subjective, since my sensations of light and sound are so. None of you are there outside me in the way I see you. Only the oscillations in the air, between you and me, lead me to the oscillations that are there in you, and I am led to the conclusion that all your inner being and life of soul — which, within you and for yourselves, is surely not to be denied — is not there at all. For me, this inner soul of everyone of you who are here seated is only the effect on my own psyche, while for the rest, all that is really there, seated on these benches, are so many heaps of vibrations. If you deny to light and sound the inner life and being which you experience in a seemingly subjective way, it is precisely as it would be if, having you here before me, I looked on all that is before me as merely part of my subjective life, and thus denied to you the experience of inner life and being.
What I have now been saying is indeed so obvious, so trite, that physicists and physiologists will naturally not presume that they could ever fall into such obvious mistakes. And yet they do. The whole distinction that is usually made of the subjective impression (or whatsoever is alleged to be subjective) from the objective process, amounts to this and nothing else. It is of course open to the physicist to be quite candid and to say: I, as physicist, am not proposing to investigate the sound or tone at all; I do not enter into what is qualitative. All I am out to investigate are the external, spatial processes (he will not have to call them “objective processes” for that again would beg the question). All I am out to investigate are the outwardly spatial processes, which of course also go on into my own body. These are the subject-matter of my researches. These I abstract from the totality; what is qualitative is no concern of mine. A man who speaks like this is at least candid and straightforward, only he must not then go on to say that the one is “objective” and the other “subjective”, or that the one is the “effect” of the other. What you experience in your soul, — when I experience it with you it is not the effect upon me of the vibrations of your brain. To see through a thing like that is of untold significance; nothing could be of greater importance for the requirements of the new age, not only in science but in the life of humanity at large.
We ought not to be too reluctant to go into deeper questions when dealing with these matters. How easily it can be argued that the uniquely oscillatory character of sound or tone is evident if only from the fact that if I twang a violin-string a second string in the same room, attuned to the same note, will resound too, this being due to the fact that the intervening medium propagates the accompanying oscillations. Yet we do not understand what is happening in such a case unless we bring it into connection with a more widespread phenomenon. I mean the following for instance, — it has in fact been observed.
You have a pendulum clock; you wind it up and start it. In the same room there is another pendulum clock; it must, admittedly, be of a certain type. This you do not wind up. In favourable circumstances you may observe that the second clock starts of its own accord. We will call this the “mutual sympathy” of phenomena; it can be investigated in a very wide domain. The last phenomenon of this type, still connected to some extent with the outer world, could be examined far more than it generally is, for it is very frequent. Times without number you may have this experience. You are at table with another person and he says something you yourself have just been thinking. You were thinking it but did not say it; he now utters it. It is the sympathetic going-together of events (or complexes of events) in some way attuned to one-another, which is here making itself felt in a highly spiritual realm. We need to recognize the whole range of continuity from the simple resonance of a violin-string which one may still interpret crudely and unspiritually within the sequence of outer material events, to these parallel phenomena which appear so much more spiritual — as when we experience one-another's thoughts.
Now we shall never gain insight into these things unless we have the will to see and understand how man himself is placed into the midst even of so-called physical Nature. A few days ago we were demonstrating and to some extent analyzing the human eye. Today we will do the same with the human ear. As we go inward in the eye, you will remember we come to the vitreous body, which, as we said, still has considerable vitality. Then there is the fluid between the lens and the cornea. As we go inward, we were saying, the eye gets ever more alive and vital, whereas the outer part is increasingly like a piece of physical apparatus. Now we can of course equally well describe the human ear, and in a purely external sense we may aver: Just as the light affects the eye and the optic nerve receives the stimulus, so do the oscillations of sound affect the ear. They go on into the external auditory canal and beat upon the drum which forms the inner end of this canal. Behind the drum are the minute bones or ossicles, called hammer, anvil and stirrup from their appearance. That which arises (speaking in terms of Physics) in the outer world and finds expression in waves of alternate compression and expansion in the air, is transmitted through this peculiar system of ossicles to the inner ear. There is the so-called cochlea, filled with a kind of fluid, and here the auditory nerve has its ending. Before the cochlea we come to the three semicircular canals, — their planes at right angles to each other according to the three dimensions of space. Thus we can imagine the sound penetrating here in the form of air-waves and transmitted by the ossicles until it comes into this fluid. There then it reaches the nerve and so affects the sentient brain. So we should have the eye as one sense-organ, the ear — another. We put them neatly side by side, and — for a further abstraction — we may even elaborate a general physiology of the senses and of sensation.
But it will not seem so simple if you recall what I said recently of the whole rhythm of the ascending and descending cerebrospinal fluid and how it interacts with what is taking place more externally in the outer air. Remember too what I was saying: a thing may look complete and self-contained when outwardly regarded, but we must not therefore take it to be a finished reality, for it need not be so at all. The rose I cut off from the shrub is no reality. It cannot be by itself. It can only come to existence by virtue of its connection with the whole rose-bush. If I think of it as a mere rose by itself, it is in truth an abstraction. I must go on to the totality — to the whole rose-bush at the very least. So too for hearing: the ear alone is no reality, though it is nearly always represented as such in this connection. What is transmitted inward through the ear must first interact in a certain way with the inner rhythm, manifested in the rise and fall of the cerebrospinal fluid. But we have still not reached the end. All this that takes its course in rhythm — and, as it were, includes the brain within its span — is also fundamental, in the real human being, to what appears in quite another part of our body, namely in the larynx and adjoining organs when we are speaking. There is the act of speaking, — its instruments quite obviously inserted into the breathing process, to which the rhythmic rise and fall of the cerebrospinal fluid is also due. In the whole rhythm which arises in you when you breathe, you can therefore insert on the one hand your active speaking and on the other hand your hearing. Then you will have a totality; it only comes to manifestation in a more intelligent or perceptive way in your hearing and in a more volitional way in your speaking. Once more, you only have a totality when you take together the more volitional element pulsating through the larynx and the more sensitive or intelligent that goes through the ear. To separate the ear on the one hand, the larynx on the other, is an abstraction; you have no real totality so long as you separate these two. The two belong together; this is a matter of fact and you need to see it. The physiological physicist or physical physiologist who studies the larynx and the ear apart from one-another proceeds as you would do if you cut up a human being so as to bring him to life instead of seeing things in living interaction.
If we have recognized the facts, this is what we shall see:— Consider what is left of the eye if I first take away the vitreous body and also the whole or at least part of what is here spread out — the retina (Figure IIIf). If I were able to remove all this, what would be left would be the ciliary muscle, the lens and the external liquid — the aqueous humour. What kind of organ would that represent? It would be an organ, my dear Friends, which I could never compare with the ear if I were thinking realistically, but only with the larynx. It is not a metamorphosis of the ear; it is a metamorphosis of the larynx. Only to touch upon the coarsest aspect: just as the muscles of the larynx take hold of the vocal chords, widening or narrowing the aperture between them, so do the ciliary muscles with the lens. The lens is inherently mobile and they take hold of it.
So far I should have separated-out what is larynx-like, so to speak, for the ethereal, even as the larynx is for the air. And if I now reinsert first the retina, then the vitreous body, and then for certain animals the pecten, which man only has etherically, or the falciform process, (blood-bearing organs, continued into the eye in certain lower animals), — this part alone I shall be able truly to relate to the ear. Such things as the expanding portions of the pecten, these I may rightly compare to what expands in the ear, — in the labyrinth and so on. Thus, at one level in the human body I have the eye. In its more inward parts it is a metamorphosed ear, enveloped from without by a metamorphosed larynx. If we take larynx and ear together as a single whole, we have a metamorphosed eye upon another level.
What I have now been pointing out will lead us presently along a most important path. We can have no real knowledge of these things if we relate them falsely to begin with by simply placing eye and ear side by side, whereas in truth the ear can only be compared to the part of the eye behind the lens — the inner and more vital part — while that which reaches farther forward and is more muscular in character must be related to the larynx. This of course makes the theory of metamorphosis more difficult. It is no use looking for metamorphoses in crude, external ways. You must be able to see into the inner dynamic qualities, for these are real.
If it be so however, my dear Friends, we shall no longer be able to conceive as parallel, without more ado, all that goes on in the phenomena of tone and sound on the one hand and on the other hand the phenomena of light. Having begun with the mistaken premise that eye and ear are equally sense-organs, we shall be no less mistaken in our approach to the related phenomena. My seeing in effect is fundamentally different from my hearing. When I am seeing, the same thing happens in my eye as when I hear and speak at the same time. Here, in a higher realm, an activity which can only be compared to the activity of speech accompanies the receptive activity as such — the perceiving, receiving activity of the eye. You will get nowhere in these realms unless you apprehend what is real. For if you once become aware that in the eye two things are welded together which are assigned to seemingly distinct organs of the body in sound or hearing, then you will realize that in seeing, in the eye, we have a kind of monologue, — as when you converse and come to an understanding with yourself. The eye always proceeds as you would do if you were listening intently and every time, to understand what you were hearing, you first repeated it aloud. Such is the eye's activity, — it is as though you were listening to someone and at the same time repeating what you heard, word for word. The other person says, “he writes”, but this does not suffice you. You first repeat aloud, “he writes”, — then and then only is the thing complete. So it is with the eye and the phenomena of light. What comes into our consciousness as an outcome of this whole complex — namely through the fact that we have the more vital, inner part of the eye to begin with — only becomes the full experience of sight, in that we reproduce it in the portion of the eye that corresponds to the larynx and that lies farther forward. Etherically we are talking to ourselves when we are seeing. The eye is engaged in a monologue, and it is wrong to compare the outcome of this monologue — in which the human being's own activity is already contained — with hearing alone, for this is but a single factor of the dual process.
I do believe, dear Friends, that if you work it through for yourselves this will give you much indeed. For it will shew you among other things how far astray materialistic Physics goes and how unreal it becomes in its study of the World, in that it starts by comparing what is not directly comparable — the eye and ear in this instance. It is this purely outward way of study — failing to look and see what are totalities and what are not — which leads away from any spiritual view of Nature. Think for example of what Goethe does at the conclusion of his Theory of Colour, where in the chapter on the “Ethical-Aesthetical Effects of Colour” he evolves the spiritual logically from what is physical. You will never do this if you take your start from the colour-theory of modern Physics.
Now I admit that sound or tone may cause misgivings. Is it not evident that in the outer world mere oscillations are going on when you hear sound? (In some such words it will be stated.) However, ask yourselves another question and then decide whether the very putting of it does not give the answer. Might it not be as follows? Suppose you had a globe or bell-jar, full of air, provided with an aperture and stopcock. Open the stopcock, — nothing will happen if the air inside has the same density as outside. But if there is a vacuum inside, plenty will happen. Air from outside will whistle in and fill the empty space. Will you then say that the air which the globe now contains came into being simply by virtue of what was going on inside the globe? No. You will say: This air has come in from outside, but the empty space — purely to describe the phenomenon as you see it — has somehow sucked it in.
So also when we turn this disc and blow against the holes, we create the conditions for a kind of suction to arise, — this is a true way to describe it. The tone, the sound that will appear when as I work the siren I cause the air to oscillate, — this tone is already in existence, only it is outside of space. It is not yet in space. The conditions for it to enter space are not given until I make them, even as the conditions for the outer air to get into the globe are not given until I make them. The outer air-waves can only be compared to the vacuum inside the globe, and what then grows audible can only be compared to what penetrates from the surrounding space into the vacuum inside when the conditions have been created for this to happen. In essence the air-waves have no more to do with the sound than that, where these waves are, a process of suction is produced to draw the sound from its non-spatial realm into the spatial. Of course the kind of sound, the particular tone that is drawn in, is modified by the kind of air-waves, but so too would it modify what happens in the evacuated globe if I made special-shaped channels in the aperture by which the air is to be drawn in. The air would then expand into the inner space along certain lines, of which an image was there. So have the processes of sound or tone their external image in the observed processes of oscillation.
You see from this, dear Friends, the fundamentals of a true Physical Science, which we aspire to, are not so easy to conceive. It is by no means enough to entertain a few mathematical notions about wave-movements or oscillations. We must make greater demands on the qualitative element in human thinking. If such demands are unfulfilled, we only get once more the picture of the World which is so worshipped in the Physics of today, and which is to reality as is a tissue-paper effigy to a living man.