A tree falls in the forest

Abstract: A tree falls in a forest, casting doubt on its existence despite the noise produced.

Inseparable and unadjustable halves

The double look, what is it exactly? Let’s start with a classic riddle: “If a tree falls in an uninhabited forest, does it make a sound?” The answer “Yes, of course!” is not suitable. The falling tree does produce vibrations in the air called sound waves, but these are only translated into “noise” if a living being with auditory receptors is nearby to perceive them. ‘Noise’ and ‘air vibration’ designate the same phenomenon from two different perspectives. The downward look is that of the person perceiving the noise —in this case it is rather a question of downward hearing. The upward look is that of the air molecules shaken by the fall of the tree, which experience a displacement.

The two looks indicate very different things, a highly significant event for one and a simple movement for the other, and yet they indicate the same thing. Can we reduce one to the other? Especially not ! We would lose half the information on the thing. We would even lose everything, in fact, because the two views being radically foreign in nature towards each other, they do not together form ‘halves’. No more than half a face and half a rock are halves of each other, or would give information about the other.

Constitute and describe

The upward look uses the quantitative and the downward the qualitative. Even the numbers do not have the same meaning for both. They are constitutive bottom-up, founding the relationships between things. They are descriptive top-down, number and qualify. Bottom-up language is mathematical, soulless, self-generated. The top-down language is multiform, flowery, the one designates the unique, the exceptional, the zero has no existence, the constitution is packed in a host of qualities.

Our riddle at the beginning takes advantage of the separation of the two looks. The answer “Yes, the tree makes noise” is obvious for the downward look, the most spontaneous in any owner of two ears. The catch is that the forest is “uninhabited.” No downward look. All that remains is the upward, which notices a vibration of the air but no ‘noise’. But the riddle is fundamentally false. The two views are inseparable. By each providing their own answer, they are necessarily right… from their point of view. And we have just seen that they are not reducible to one another.


The correct answer to the riddle is “yes and no.” Certainly the forest is uninhabited but it is only ‘forest’ for the human being who thinks of it that way. Likewise, it takes a human to think about the vibration of the air, which is therefore not as independent as it seems. In the riddle there is always a mind lying in wait, and not just the nature of things in themselves. ‘Noise’ and ‘air vibration’ are two different levels of representation of the mind, two aspects of something that is not accessible in its essence. Even our most advanced theories do not allow access to it, because they are more fundamental levels but still representations of this essence.

Let us be careful not to say that this essence does not exist because then the riddle would have to be answered: “There is no noise because there is no falling tree.” There would actually be nothing. Our representations would fall into nothingness, because we would not recognize an origin in the upward look that we try to simulate with our theories. Let us quickly restore an essence to things, and accept that it is inaccessible to us, this is one of the “essential” lessons of the double look.


5 thoughts on “A tree falls in the forest”

  1. So, this is a very old thought experiment, isn’t it.? Like the price of the ballbat and ball…but, older. The thing about classic thought experiments is they have no right or wrong answer. Any answer is contingent upon interest, motive and preference(s) (IMPs). Any way we cut it, when something makes noise, something sentient will notice. A rock or tree won’t pay attention. A deer or squirrel will. Yes and no, then, resembles the attorney’s response to a legal question: it depends. Therefore, within elementary parameters, yes and no is a philosopher’s response. Philosophers always make things harder than they are. As Wilber used to say, and just so. It is just not fun if it is easy, is it?

  2. You’re right, Paul, except that ‘yes’ and ‘no’ are both good answers simultaneously and not context-dependent. The two looks surround the world between their opposing starting points. Answering yes and no to the same question is only contradictory for a single look, not the double.

    • As you will, JeanPierre. I have been reading another exchange, on a different blog, dealing with CNS, or , cosmological natural selection. That may or may not merit a double look. But it is, apparently, attracting more than one look and includes thought from than one century; thinkers go back many. I have argued, indirectly, that cosmology, physics and the rest are not natural forces in the sense of the forces which spawned life. Here, or anywhere else it may be. Oxygen and hydrogen appear to be the keys. Elemental ,my dear Watson. My approach entails a second thought, rather than a double look. Same thing? Or not. We make our own distinctions. I am not asserting there are no silicon-based life forms. Or, that they would get thirsty. I just don’t know what I don’t know. Do you?

  3. I wanted to add something to your double look scenario. Remember the duck/rabbit; shifting cube; old woman/ young lngenue looks we learned? There were dozens of them. Were those double looks, or, second looks? See, I don’t know. My best sense says you have something . I just do not know what it is. Certainly, you owe me no explanation. That is not my point here.

    • The duck/rabbit or old/young woman illusions are good illustrations of the double look… in the sense that they are mental representations that compete with each other in our brain. The visual centers offering a single scene to consciousness are forced to make a choice between the two representations. Our brain can alternate between them but not see them simultaneously.

      Now suppose that the two representations can coexist, that they are not exclusive of each other. The philosophical double look is rather that. In particular, in the way of thinking that I propose, it is to combine the look at the micromechanisms of a thing and the look at its final properties.

      As with the duck/rabbit image, these are two representations of the same thing. One comes from science, from our fundamental theories. The other comes from daily observation. Two mental representations compete with each other and do not have the same mental fame among the scientist and the layman, just as the duck or the rabbit wins in turns depending on the brain.

      But both are essential. If you miss one of them, you cannot properly understand the thing that is experienced as the entanglement of the two representations. This is particularly damaging for the mechanisms/properties duality that the double look reveals.


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