Sense of movement

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The sense of movement or sense of self-movement and body position[1], also referred to as proprioception, kinaesthesia (or kinesthesia) and muscle sense[2], is one of the twelve physical senses that Rudolf Steiner spoke of in his theory of the senses and conveys the perception of one's own bodily movement.

Connection with the etheric body, life spirit and astral body

The activity of the sense of self-movement is essentially based on the fact that the etheric body is permeated by the life spirit. This creates a balance in the etheric body and then in the physical body, which also results in a balance in the astral body. With every movement of the physical body an astral current flows back in the opposite direction. In the inner experience of this process the sense of self-movement reveals itself.

„The second sense we have mentioned is the sense of self-movement. Here again something is at work in the etheric body of man which we do not yet possess consciously. And again we can use the parable of the sponge. Here, too, the etheric body is saturated and permeated like a sponge by water, and what now permeates and permeates it is the life-spirit or the Budhi, which it will one day develop out of itself. Today, of course, this is only given to us, as it were, provisionally from the spiritual world. The Budhi or life spirit works differently from the spirit man. It works in such a way that a balance occurs in the astral body, as in the water at rest in itself. The equilibrium in the etheric body and then in the physical body results in a balance in the astral body. If this equilibrium is disturbed from outside, it tries to balance itself again. When we make a movement, what has become unbalanced is rebalanced. For example, if we stretch out our hand, an astral current flows back in the opposite direction of the outstretched hand, and it is the same with all movements in our organism. Whenever a change occurs in a physical situation, an astral current moves in the organism in the opposite direction. So it is with the blinking of the eyes, so it is with the moving of the legs. In this inwardly experienced process of a balance in the astral body, the sense of self-movement reveals itself.“ (Lit.:GA 115, p. 36f)

Depth sensitivity

In German medical literature, this perception is now called depth sensitivity, which, together with the sense of balance, enables proprioception (from Latinproprius "own" and recipere "to take up"), the perception of one's own body movement and position in space[3]. For this purpose, proprioceptors register muscle tension (Golgi tendon organ), the degree of stretch of the muscle or muscle length and its rate of change (muscle spindle) as well as joint position and movement (Ruffini corpuscles); the Vater-Pacini corpuscles (Pacinian corpuscles), which are mainly located in the subcutis, are particularly sensitive to vibration sensations.

The sense of movement, together with the sense of touch and/or the sense of sight, is decisively involved in the perception of external forms.

Depth sensitivity includes:

  • Position sense, which provides information about the position of the body in space and the position of the joints and head.
  • Force sense, which provides information about the state of tension of muscles and tendons.
  • Sense of movement (or kinaesthesia, from the ancient Greekκινειν kinein "to move" and αίσθεσις aísthesis "perception"), through which a sensation of movement and recognition of the direction of movement is made possible.

The sensory task of the so-called motor nerves

According to Rudolf Steiner, the so-called motor nerves, which according to the established neuroscientific thesis serve to "control" bodily movements, have, like all other nerves, an exclusively sensory task and serve the more or less dull perception of one's own movements. Thus the "motor" nerves also fall into the realm of the sense of one's own movements.

„This materialistic scientific attitude believes that just as it requires the mediation of the nerves for sensation, for perception, it also requires the mediation of the nerves for the impulses of the will. But this is not the case. The impulse of the will proceeds from the spiritual-mental. There it begins, and it acts in the body, directly, not by the diversions of the nerve, directly on the limb-metabolic system. And the nerve that goes into the limb-metabolic system only mediates the perception of that which the spiritual-soul does in the whole human being in relation to his limb-metabolic system. We perceive that which is a consequence of soul-spiritual will processes in the blood circulation, in the rest of the metabolism and also in the mechanical movement of the limbs; we perceive that. The so-called motor nerves are not motor nerves, they are merely that which perceives the expressions, the impulse of the will. Until one understands this connection, one will not arrive at a transparent knowledge of man.“ (Lit.:GA 303, p. 209)

That the nerves must have different directions of conduction (efferent and afferent) is expressly emphasised by Rudolf Steiner - but this has nothing to do with the alleged difference between sensory and motor nerves.

„Reasonable naturalists have therefore already assumed that every nerve has a conduction not only from the periphery inwards or vice versa, but always also a conduction from the periphery to the centre, or from the centre to the periphery. In the same way, every motor nerve would then have two lines ...“ (Lit.:GA 312, p. 57f)

The reflex arc as a fundamental model of the nervous system is the basis here, but Rudolf Steiner interprets it in a completely different way than is usual in neuroscience. The interruption in the reflex arc in no way signifies the transition from the sensory to the motor nerve, but rather the spiritual-mental aspect of the human being is intervened here in the living organism and forms the transition from physical to spiritual experience. This is a fundamental insight of [8spiritual science]].

„I have often referred to an idea, publicly now also in my book "Von Seelenrätseln": It is a viable scientific conception today that in the nervous system - let us stay with man for the moment, but in a similar way, only in a similar way is this also valid for animals - that one distinguishes in the nervous system between so-called sensitive nerves, sensory nerves, perceptive nerves and motor nerves. Schematically this can only be represented in such a way that, for example, some nerve, let us say a tactile nerve, carries the tactile sensation to the central organ, let us say to the spinal cord (yellow), where that which is conducted from the periphery of the body flows into a horn of the spinal cord. And then from another horn, the anterior horn, comes the so-called motor nerve, which in turn transmits the impulse of will (see drawing p. 12).

Drawing from GA 179, p. 12
Drawing from GA 179, p. 12

In the case of the brain, this is only represented in a more complicated way, as if the nerves were a kind of telegraph wires. The sensory impression, the skin impression, is conducted to the central organ, where the command is given, so to speak, that a movement should be carried out. A fly settles somewhere on a part of the body, that makes an impression, that is conducted to the central organ; there the command is given to raise the hand to the forehead and the fly is chased away. It is a very practicable idea, schematically indicated. To future times this idea will seem extraordinarily funny, for it is only funny to those who see through the fact. But it is an idea of which a large part of the most expert and professional science is now dominated. You can open the next best elementary book that teaches you about such things, and you will find that one has to distinguish between sensory nerves and motor nerves. And you will find especially the hilarious picture of the telegraph lines - how the impression is conducted to the central organ and there the order is given for the movement to arise - still very common today, especially in popular works.

Reality, however, is more difficult to look through than the comparative ideas of the telegraph wires, which are reminiscent of the most primitive imaginings. Reality can only be seen through if it is seen through with spiritual science. The fact that an impulse of the will takes place has really nothing whatever to do with such a process, which is childishly expressed as if an order were given somewhere in a material central organ. The nerves are only there to serve a uniform function, both those nerves which are now called sensitive nerves and those which are called motor nerves. And whether the nerve cord is broken in the spinal cord or in the brain, both indicate the same thing; in the brain it is only broken in a more complicated way.

This interruption is not there so that through one half, if I may say so, something is conducted from the outer world to the central organ and then, after it has been transformed into a will by the central organ through the other half, would be passed on. This interruption is there for quite another reason. The reason why our nervous system is so constructed and so regularly interrupted is that at the point where our nerves are interrupted there lies in the image in man - though only in the physical image of a complicated spiritual reality - the boundary between physical and spiritual experience, physical and spiritual experience. However, it is contained in the human being in a strange way. It is contained in such a way that the human being enters into such a relationship with the physical world which lies first to him that the part of the nerve cord which goes up to that interruption has something to do with this relationship. But man, as a spiritual being, must also have a relationship to his own physical body. This relationship to his own physical body is mediated by the other part. When I move a hand, prompted by the fact that an external sense impression has been made upon me, then the impulse for this hand to be moved, united by the soul with the sense impression, schematically represented, already lies here (see drawing, a). And that which is conducted is conducted along the whole of the sensory nerves and the so-called motor nerves, from a to b. It is not in this way that the sensory impression first goes up to c and then from there gives a command so that b is induced to do so - no, when an impulse of will takes place, the psychic already lives fertilised at a and passes through the whole interrupted nerve path.

There is no question of such childish ideas, as if the soul were sitting somewhere between the sensory and motor nerves and, like a telegraphist, receiving the impressions of the outer world and then sending out orders; there is no question of these childish ideas corresponding to any reality whatsoever. This childish idea, which we always hear, seems quite strangely comical next to the demand that one should not be anthropomorphic in natural science! People demand that one should not be anthropomorphic and do not notice how anthropomorphic they are when they use words like: An impression is received, an order is issued and so on. - They talk about it without having the slightest idea of what mythological beings - if they were to take the words seriously - they are dreaming into the human organism.

But now the question arises: Why is the nerve cord interrupted? - It is interrupted for the reason that if it were not interrupted, we would not be involved in the whole process. It is only because the impulse jumps over at the point of interruption - the same impulse, if it is an impulse of will, already emanates from a - that we ourselves are inside the world, that we are present with this impulse. If it were uniform, if there were not an interruption here, the whole would be a natural process without our being present.

Imagine the same process that you have with a so-called reflex movement: A fly sits down somewhere, you are not fully aware of the whole process, but you repel the fly. This whole process has its analogue, its quite justified analogue in the physical field. In so far as this process calls for physical explanation, this explanation must only be somewhat more complicated than another physical process. Suppose you have a rubber ball here, you push into it, you deform the rubber ball: it comes out again, straightens up again. You poke it again; it pokes out again. That is the simple physical process: a reflex movement.

Drawing from GA 179, p. 15
Drawing from GA 179, p. 15

Only no organ of perception is switched in, nothing spiritual is switched in. If you switch in something spiritual here (inner circle) and interrupt it here (centre), then the rubber ball feels like a being of its own. However, the rubber ball would then have to switch in a nervous system in order to feel both the world and itself. But the nervous system is always there to feel the world within itself, never somehow there to conduct a sensation on one side of the wire and to conduct a motor impulse on the other side of the wire.

I am hinting at this because, if pursued further, it leads to one of the numerous points where natural science must be corrected if it is to lead to conceptions that are to some extent equal to reality. The ideas which prevail today are nothing more than such ideas, which serve the impulses of the spirits of darkness. In man himself is the boundary between physical experience and spiritual experience.

This part of the nerve, which I have called red, serves essentially to place us in the physical world, to give us sensation within the physical world. The other part of the nerve, which I have called blue, serves essentially to make us feel ourselves as a body. And there is no essential difference whether we consciously experience a colour externally through the strand a-c, or whether we experience an organ or a layer of organs or the like internally through the strand d-b; it is essentially the same. One time we experience a physical thing that does not appear to be within us, the other time we experience a physical thing that is within us, that is, within our skin. In this way, however, we are enabled to experience everything that is not only outside us, but also what is inside us, during a process of will. But the strength of perception is mediated differently through the strand a-c and through the strand d-b. That which occurs, however, is an essential weakening of intensity. If we form a conception together with an impulse of will in a, then this impulse is transmitted from a. As it jumps from c to d, the whole thing weakens so much for our consciousness, for our conscious experience, that we experience the rest of what we now experience in ourselves, the raising of the hand and so on, only with the low intensity of consciousness that we otherwise also have in sleep. We only see the will again when the hand moves, when we again have a sensation from another side.“ (Lit.:GA 179, p. 11ff)

Literature

References to the work of Rudolf Steiner follow Rudolf Steiner's Collected Works (CW or GA), Rudolf Steiner Verlag, Dornach/Switzerland, unless otherwise stated.
Email: verlag@steinerverlag.com URL: www.steinerverlag.com.
Index to the Complete Works of Rudolf Steiner - Aelzina Books
A complete list by Volume Number and a full list of known English translations you may also find at Rudolf Steiner's Collected Works
Rudolf Steiner Archive - The largest online collection of Rudolf Steiner's books, lectures and articles in English.
Rudolf Steiner Audio - Recorded and Read by Dale Brunsvold
steinerbooks.org - Anthroposophic Press Inc. (USA)
Rudolf Steiner Handbook - Christian Karl's proven standard work for orientation in Rudolf Steiner's Collected Works for free download as PDF.

References

  1. Tuthill JC, Azim E (March 2018). "Proprioception". Current Biology. 28 (5): R194–R203. doi:10.1016/j.cub.2018.01.064. PMID:29510103.
  2. According to a notebook entry by Rudolf Steiner; cf. GA 115, p. 315
  3. Buser K., e.a.: Kurzlehrbuch medizinische Psychologie- medizinische Soziologie, Urban&FischerVerlag, 2007, p.93, ISBN 3437432117, [1]