Socrates Up to Date: A Dialogue Regarding Cause and Effect

SOCRATES. What caused that unearthly screeching I heard all night long ?

CRITO. It was Phædo’s street sign just below your bedroom.

S. That cannot be, for the sign is there now, overhanging the street, but I do not hear the annoying sound.

C. The reason you heard it last night and do not hear it now is that during the night it was swaying in the wind, but this morning it is motionless.

S. Then it was not the sign, but its motion, that was the cause of the offending noise.

C. Well, if you have to be so precise about it, let us say that the swinging or motion of the sign was the cause of the noise. The next time I see Phædo I shall tell him I consider it an imposition to annoy the neighborhood with his creaking sign, when by dropping a little oil on the rod supporting it the sound would be done away with.

S. How could the drops of oil stop the sign from swinging in the wind?

C. The oil would not stop it; it would cause it to swing more freely by reason of the lubrication.

S. But I thought, to correct your first statement, you said it was the swinging or moving of the sign that caused the noise?

C. To be exact about it, I must beg leave again to amend my explanation of the cause. It was the friction produced by the moving parts of the sign and supporting rod that caused the sound. To save you the trouble of asking another question, I will explain more fully, in anticipation, that the friction so produced causes minute rapid undulating movements of the supporting rod, which movements set in motion the surrounding atmosphere in the form of waves, which waves, beating against your tympanum, or eardrum, produce the sound.

S. I hope I understand you now. If my eardrums were removed, there would be no sound.

C. In such case you would not hear the sound, but of course there would be sound, nevertheless, which would be heard by others.

S. Suppose my eardrums were skillfully removed, and I held them on the palm of my hand; the waves beating against them would produce the sound to be heard by others?

C. No, not that. To have anything to do with the sound the drums must be intact and functioning properly as auditory organs of the body.

S. Then the cause of the sound is really the activity of the auditory nerves operating on what is indefinitely known as the sensorium of the brain, or whatever it is that gives me the sense of hearing?

C. Exactly.

S. In the last analysis, therefore, the sensorium is the cause of the sound, for if it were removed or paralyzed there would be no sound, limiting the argument to my experience only?

C. No; the sensorium is not a cause.

It is the name given that part of your being or physical organization that hears. Whatever happens with respect to it — giving you the sensation of sound, for instance is purely an effect.

S. I see. May we be sure that the activity of the auditory nerves is not an effect rather than a cause?

C. Certainly it is a cause, for this activity produces the effect in the sensorium known to us as sound.

S. Now I am confused again. Is sound something that we hear ?

C. Why, of course.

S. Then it must be something distant and apart from ourselves and our hearing, for how otherwise could we hear it?

C. Well, it might seem that way. But are n’t the sound and the hearing the same thing? We cannot hear anything but sound.

S. Would you say that light and seeing are the same thing, or would you say that light is a distinct phenomenon by means of which we see various things?

C. Light is a means of vision, of course, but when we look at a thing all we see is the light bouncing off the surface.

S. Your conclusion is that light is simply a sensation?

C. I so conclude.

S. What produces the change on the sensitized camera film when a picture is taken?

C. The light.

S. Was anyone, or the camera, conscious of the light while this change was taking place?

C. I suppose not.

S. Then light must exist independently of our sensation of it?

C. It would seem so.

S. What produces the indentations on the phonograph recording plate or cylinder when talked into?

C. The undulating waves of atmosphere beating against the diaphragm holding the recording needle.

S. Those undulating waves of atmosphere beating against the diaphragm holding the recording needle are commonly known as sound, are they not? It is the sound that is recorded ?

C. What is heard is sound, but the vibrating of the recording needle makes the record; the vibrations are what are recorded.

S. Yes, and when this same vibrating is reproduced by the movement of the record you hear the sound, do you not?

C. What we hear is sound, but the vibrations are a mechanical phenomenon. I want to retract my admission that light exists independently of sensation. The change on the sensitized film is the result of vibrations of the same mechanical nature as sound, but finer and more rapid.

S. Then if all living things became deaf and blind, there would be no such thing as sound or light?

C. That would be about it.

S. You just said that all we know about a thing through vision is the light reflected from it.

C. Yes, and that is a fact.

S. Do we know anything except through vision, hearing, smelling, tasting, or touching?

C. No.

S. If these five senses were destroyed, all material objective things would cease to exist, would they not?

C. We should cease to have any sensation of them, but they would still exist.

S. How would you know they existed?

C. Probably I should n’t know it, but they would exist just the same.

S. How can you say a thing exists if you do not know it?

C. I don’t know.

S. This brings us to the idealist’s theory that nothing exists except our conception or impression of it, and a step further to the conclusion that with the conception gone everything would cease to exist.

C. What has all this to do with sound and its cause?

S. You objected to sound being considered as something distant and apart from ourselves, and asserted that sound and hearing are the same thing, which would make sound purely subjective. Following this line of reasoning, we have now made all things subjective, — that is, merely impressions of the senses, — so that nothing is left to be objective or distinct from our sensations. In other words, not only are sound and hearing the same thing, but every object and our sense of it are the same thing, thus wiping them all, sound and objects, out of existence, or forcing us to admit that, if sound is something we hear, it must be something distant and apart from ourselves, just as material objects are.

C. I never could understand the idealist’s theory.

S. Nor anyone else. To accept it requires simply to believe it, and it can be accepted on no other basis; and the same may be said of the materialist’s theory. It is impossible for the idealist to convince the materialist, and as impossible for the materialist to refute the idealist’s theory, because they cannot work with each other’s tools of thought; they have no common ground to stand on. We must arbitrarily take one side or the other and stick to it.

C. Well, I prefer to think that objects exist whether I see them or not, because many things that people saw a thousand years ago but do not see now I see, so they exist; likewise when I have ceased to live, and therefore to see, others living after me will see them, though I do not.

S. Then we had better consider sound the name of that particular vibratory phenomenon which is known to us through hearing?

C. Yes.

S. Now are we to consider the activity of the auditory nerves an effect?

C. No; it causes the effect in the sensorium.

S. What does the vibration in the eardrum do?

C. It must be that it generates the auditory-nerve activity. I see your point. Yes, the nerve activity would be an effect, looking at it that way.

S. Would not the vibration in the eardrum be the effect of the waves of atmosphere you referred to?

C. Yes, that is so, too.

S. And these waves are the effect of the friction on the supporting rod of the sign?

C. Yes.

S. Likewise the friction is an effect of the motion of the sign?

C. Yes. Now I hope we have reached the bottom of it.

S. All these things we have been calling causes are really effects, are they not?

C. Well, they are causes in one sense and effects in another. Each is the cause of the next thing that happens and the effect of what happened just before it. But the sensorium’s activity is the final effect, and not a cause, and the motion of the sign is the originating cause, and not an effect.

S. At first you said the cause of the sound was the swaying of the sign in the wind. Was not the wind really the cause and the sign’s motion an effect?

C. Yes, I suppose that is right; the wind is really the cause.

S. Meteorologists tell us that low pressure at given points on the earth’s surface causes the surrounding atmosphere to rush toward these points, and that this rushing in is what we observe as the wind. So the wind would be an effect of these low-pressure points and the surrounding higher-pressure areas? C. Yes.

S. And these low-pressure points are produced by excessive heat, making them effects and heat the cause?

C. Yes, that is what they claim.

S. The heat referred to is generated by the sun. Therefore the sun was the cause of the noise that kept me awake last night?

C. Yes — and this is the malt that lay in the house that Jack built.

S. Come to think of it, by sun we mean that heavenly body composed of chemical elements in a superintense state of agitation; so, after all, this activity of the elements in the sun was the cause?

C. No. It was the law of molecular energy or whatever causes the elements to become active. What next?

S. I hope I am not wearying you with this extended analysis of cause and effect.

C. Not at all. But if I had it to do over again I should grease the sign before you went to bed.

S. That reminds me that we overlooked the real cause of the noise. Was it not the failure of Phædo to oil the bearings of the sign, as you suggest?

C. As much as anything else.

S. And his want of thoughtfulness for the comfort of others was the cause of his failure to oil the sign?

C. Certainly.

S. Probably his great concern in other matters preoccupying his mind was the cause of this thoughtlessness?

C. Yes, and his self-interest involved in these other matters caused his mind to be preoccupied, and self-interest is caused by heredity or some universal law of living things.

S. Very good. It would seem from our experience in trying to analyze cause and effect that searching for an ultimate exclusixe controlling cause is futile. Probably we should have taken your first explanation, namely, the sign itself, as the cause, it being the prominent thing and most closely connected with the sound in question. Strictly it was not the cause of anything, but we can make it serve as a sort of symbol to represent those activities most closely connected with the event and preceding it in existence, being the most immediate obvious tangible factor.

C. Yes, but ought we not to find out who made the sign, who or what prompted him to make it, and what moved the person or thing to prompt him ?

S. No, we had better not, because there would yet remain uninvestigated what produced the materials out of which it was made, or how the maker learned to construct signs. Cause would seem, after all, to be merely a form of thought, a mental instrumentality for carrying on thought and for accomplishing practical purposes, a purely relative term.