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.