To catch a falling tree

It’s a nice, hot summer evening and I’m sitting here, inside, looking at my computer screen. I could have gone out to catch some of the wind that just manages to move the leaves and the smallest branches on the tree outside my window, but I’m not doing that because I’m blogging. I have promised myself to post an article every three days and tomorrow is one of those days. I find I have lots of ideas but they simply haven’t matured enough. My eyes keep drifting towards the world outside until I feel like my vision is blocked by this tree that I know and love. How weird.

A Sycamore Tree, by Asher Brown Durand [Public domain]

A Sycamore Tree, by Asher Brown Durand [Public domain]

the lonely tree

Imagine a tree falling down. No one there to hear it, man or beast. Does that tree make a sound? Apparently, the question was first asked in the early 1700’s. At the time, the tree was stood in a park and this was the answer:

“If a tree falls in a park and there is no-one to hand, it is silent and invisible and nameless.” William Fossett

The tree has since acquired a page in Wikipedia, so we can’t maintain that nobody noticed it. There are people who believe this question cannot be answered, but that’s not true. It just proves that many of us find unanswerable questions easy to live with.

When I first heard this question, I soon forgot all about the tree and felt lonely. Many of the things I did during an ordinary school day lost their meaning because there was no one there to witness them. My best friend told me God was watching her every move and that changed my mind: my being alone could mean there were no rules!

However, I was still stuck with the tree. I asked a few grownups and they told me it was an annoying, pointless question. It seemed to make them uneasy.

only the mind moves

The large oak tree forest of Fontainebleau, by Théodore Rousseau [Public domain]

The large oak tree forest of Fontainebleau, by Théodore Rousseau [Public domain]

I then wondered if my observing would make any difference to the tree. I imagined the tree having already produced its seeds and provided shade for the tender green shoots that were its next generation. From an evolutionary perspective, it would be ready to die. My witnessing its fall was a one-way street: trees communicate with their environment, but humans mean nothing to them.

“What do you mean by a one-way street? Quantum physics has given us new ways to look at the observer and the tree.”

Even without quantum physics, some people would turn the problem around and say the tree only existed in my mind. It would die with me, when I forgot about it. This is a description from the Mumonkan collection of zen koans about a flag, waving in the wind.

“Two monks were arguing about the temple flag waving in the wind. One said, “The flag moves.” The other said, “The wind moves.” They argued back and forth but could not agree.The Sixth Ancestor said, “Gentlemen! It is not the wind that moves; it is not the flag that moves; it is your mind that moves.” The two monks were struck with awe.”- The Mumonkan Case 29, translation by Robert Aitken

philosophical analysis of the question

The best explanation I found shows how anyone can solve this problem. It’s not about the observer, nor is it about the tree. We should focus on the sound and analyse that part of the original question. We should look at sound as a concept.

HongKong Central Market, by FebSquare [CC-BY-SA-3.0 (]

HongKong Central Market, by FebSquare [CC-BY-SA-3.0 (

I found the following answer on a university website aiming to explain what philosophy is about and I’ll quote it in it’s entirety. Not because I’d expect any of my readers to not be able to answer this particular question, but because it shows how you can think about a simple problem in a rigorous way and hopefully move on to other problems. It’s brilliant that we humans have ways to think laterally, but sometimes it helps to think straight.

The answer to the question was found under the heading Philosophical Analysis

“The question to be answered is: Does the falling tree, when it hits the ground, make any sound?”

“On first take, some want to answer that obviously the tree will make a sound. After all, sound is something objectively real which shouldn’t need the presence of a perceiver to occur, even if it is true that we’ve never heard a sound that we didn’t hear. Even the sound we didn’t hear could be evidenced by (say) a tape recorder placed in the vicinity. So yes, it makes a sound, or so it seems. But, in contrast, it also seems that sound is a subjective phenomenon, something not unlike a sweet taste or the feeling of pain—things that seem to require a perceiver. And so one might well doubt whether the tree really makes any sound. What should be apparent here is that “sound” has more than one meaning. That is, there is more than one concept of sound. Indeed, consider two definitions of sound, one which we might call the physics concept, and the other the psychology concept of sound.

soundphys = vibrations in a medium (such as air)

soundpsy = a sensation; an auditory experience

Study for the landing of Columbus, by Albert Bierstadt [Public domain]

Study for the landing of Columbus, by Albert Bierstadt [Public domain]

These are both legitimate definitions. The first (physics) reflects interest in sound as a physical phenomenon. The second (psychology) reflects interest in sound as a kind of experience. Notice that these two kinds of sound, though related, are different and can occur independent of each other. Normally sound as vibrations causes sound as an experience. But they can occur independently, i.e. one without the other. For example, sound as vibrations doesn’t have to cause sound as an experience (perceivers might not be present or their ears/brains might be damaged). And sound as an experience could occur without being caused by vibrations in the air (the perceiver might be undergoing some internal hallucinogenic stimulus from chemicals in the brain). Once we see the distinction between these two concepts we can see that the original question is ambiguous; it has more than one meaning. The question (Will the tree make any sound?) is really one of two questions:

(1) Will the tree make any soundphys?

(2) Will the tree make any soundpsy?

The answer to the original question depends on the sort of sound the questioner is asking about. The answer to (1) is: Yes, there will be sound in the physics sense (soundphys i.e. vibrations). The answer to (2) is: No, there will not be sound in the psychology sense (soundpsy i.e. auditory experience). So the question, once clarified, has a definite answer.”

About Pipteinpteron

Catch a falling feather. Don't keep it.
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31 Responses to To catch a falling tree

  1. Mordanicus says:

    Great analysis! Much confusion and problems in real life arise from the fact that humans are confusing different concepts by referring to it with the same name.

  2. Bastet says:

    human’s confuse life
    thinking that they are the center
    physics prove them wrong

    Thanks for another great post! The question i would ask is why do we think we are so important as to think the law of nature was created by a parenthesis of creation, humankind. 😉

    • Thank you very much for your comment and your poem, Bastet!
      It’s a good question. Even in the lifetime of planet Earth humans will probably just be the equivalent of the blink of an eye…Trees have been falling all over long before we were around to hear them. 🙂

      • Bastet says:

        Exactly…imagine, the void of space…when we no longer exist, will we have existed, if no other entity ever heard us sing, cry or shout?

  3. dyssebeia says:

    Of course, they didn’t complete the analysis! For there is at least one other sense of “make a sound”, in which it is roughly equivalent to phrases like “make a splash” or “make a noise”—i.e. was the event momentous, important, etc. And for that the answer is surely “maybe…”

    • Thank you for your comment and your insight, dyssebeia! I think you’re right. For an imaginary tree to fall and to have the sound reverberate all the way to cyberspace would be more than a “maybe” to me! 🙂

  4. Great article; it reminded me of a similar analysis that concluded the tree didn’t make a sound because sound required an ear to perceive it. Clearly they were using (2).

    My answer to the question is that it may be incoherent to begin with. When I think of sound, or a tree falling, I think of a perception of a tree falling. So to ask if a tree falls with no one to perceive its falling (be it the sound it supposedly makes or otherwise) is (in my mind at least) to ask if a tree falls without being perceived while being perceived, which is contradictory.

    At each stage of knowing, there is either a perception or inference from perception. To try to take an example completely divorced from perception and ask an apparently perceptual question…

    The question goes beyond perception and gets into ontology. To ask the question is to tackle an instance of the question of whether there is a reality beyond perception. Of course the problem with such a question is that by definition it is unanswerable since all we know is from perception (directly or indirectly).

    • Thank you for your comment, BR! I have seen many of these answers you describe, they either stopped at the psychological or at the physics side of the answer. At its best, I think philosophy should provide the overview on these things.

      Your take on the question is certainly interesting. There is a paradox there. But could there be any example completely divorced from perception?

      I think you answered that one already. 🙂 Still, I hope the thought experiment still isn’t completely meaningless.

      • Well, the question (IMO) is meaningless BUT the thought experiment (and your article) is not, because to contemplate the question is to reveal its meaninglessness (in my case) and to trigger epiphanies in ontology.

        In other words, just because a question is “meaningless” doesn’t mean it’s not worth contemplating. On the contrary, a meaningless question can teach us much more than a meaningful one.

        Most intellectual conundrums (and other paradoxes) are meaningless for the simple fact that life goes on. What they do affect is how we think about things, which in turn may (ironically) make them very meaningful on another level.

        For example, Zeno argued against motion, but we move. Clearly, Zeno’s argument is 100% irrelevant to daily life. The issue here is in how we think about the universe, and not the universe itself, which chugs along perfectly happily while occasionally thwarting our expectations to put us in our place 🙂

        Once we learn about how we fail to conceptualize (or how we conceptualize meaningless things) then that’s another way of experiencing some distance between our minds, a reminder that our minds are not perfect, and that we may not perfectly perceive reality.

        • I’ll think about this one for a bit, BR. I can follow your reasoning but an answer doesn’t immediately spring to mind.

        • Hi BR!
          I’ve given your answer a bit more thought. You mention that most intellectual conundrums are meaningless because life goes on. I wonder if life itself is meaningful in any transcendent way.

          Nietzsche looks at humans as part of nature (see the quote in my answer to Genetic Fractals) and instead of humans transcending nature, he looks at nature as making this jump through people. At the same time, there is no real separation between humans and the rest of nature, but he changes the emphasis from humans looking at the rest of nature as separate (and less conscious than humans) — the ordinary way of looking at it, to nature creating us and creating through us. At least, that was his view in his earlier writings.

          I’m not exactly sure how I feel about this, but I always like to turn ideas on their heads, so it definitely appeals to me.

          I like how you say that our minds are not perfect and that we don’t perceive reality in a perfect way. I think that is one of the important meta-answers to the question of the falling tree: our limited minds and our limited perception of reality. Thanks for mentioning that!

          • Is life meaningful in any transcendent way? Is life meaningful period? What is meaning? More tough questions with no good answers. My favorite (facetious) answer is this: the purpose of a thing is the goal towards which that thing heads; since we are all destined for death, our purpose in life is to die.

            The issue with meaning is that for X to have meaning, there must be a Y that stands above X to give it meaning. What stands above life to give it meaning? So the question itself may have no *ahem* meaning. Alternatively, we can simply take meaning as a feeling, and find our own, in which case the question stops being if life is meaningful and rather whether we found a way to live that is meaningful for us. Existentialism 🙂

            Which brings us to transcendence. The same thing applies. Do humans transcend nature? I don’t think so. If we transcend our nature in the sense that we don’t act on some of our impulses the way animals do, then maybe. In a way though, it seems we don’t so much transcend our nature as manage to channel parts of it in other directions. But since we are part of nature, to argue that we are artificial or transcend it is itself curious.

            Maybe nature does “transcend” or “observe” itself through people, although another problem here is that “nature” is itself an abstraction. What is “nature”? Answers vary depending on who you ask. What does it mean for an abstraction to observe itself?

            Yes, the value of many of these philosophical conundrums is to expand our mind, precisely by showing its limitations. Thank you for writing this article and stimulating my thought!

            • Thank you, BR. For the comment as well as the compliment. I’m thinking about blogging on ‘nature’ in the sense described here, just to make sure this is not just about trees, but I’m not sure if I know enough to make it a meaningful post. From a philosophical viewpoint, there’s a lot to be said about nature. So it’s a maybe.

              I’d be inclined to say that nature observes itself because we observe ourselves and we’re part of nature. For transcendence, I’d be looking for more than observing. I really like Nietzsche’s image of a jump. Not a passive observing, but something active that is not stuck on earth.

  5. It is an enlightening analysis and a worthwhile one. The question I would add is: isn’t physics itself a psychological description of our experience of the world? Or is it independent? I would argue that physics is as also an aspect of our conscious experience, just as hearing (or not) a tree come down. Therefore, we are back to square one: is there an independent reality outside our experience? Personally, I don’t think so. Unless there are the self-observing eyes and ears of the universe through its various life forms here and elsewhere, there is no conscious reality. All there is then is a massive energy field throughout the universe in which things have no existence or meaning at all.

    Not only does a tree not fall when there is no conscious observation; there is no tree in the first place.,..

    • Hi Genetic Fractals! If you’d ask me if physics itself is a psychological description of our experience of the world, I’d be inclined to say yes. For exactly the same reason you mention: it being an aspect of our conscious experience.
      On the question of there being no conscious reality; that is exactly the point where my beliefs have recently changed. I’ve been looking for it, but I haven’t found it. And now I think it’s an imaginary duality of the sort we humans are just likely to imagine, to find meaning where there is none… Wow, isn’t that sceptical?

      I agree with you completely about there being no ‘tree’ in the first place and I wonder if that was the point of the Mumonkan as well…

      • We are definitely the two monks in need of Mumonkan! If I understand you correctly then I wouldn’t call you a skeptic but someone who realises that that reality that makes us both happy and distressed is of our own making, not just in a happy-feely sort of way but it the realest sense. This is at once disappointing and liberating. One way to overcome the disappointment is to realise that we are quite literally the universe contemplating itself. Although it doesn’t make us God (thank goodness), it does give cosmic meaning to life. Imagine, without us (and our fellow life from viruses to soon to be revived woolly mammoths) the universe would have no awareness or be conscious of itself…!

        In practice, it changes nothing. When the tree fell in my garden, which I couldn’t hear but can attest it must have made a noise, it was a real experience. So was the gorgeous smell of pine resin as I chopped it to bits.

        It is all a game, isn’t it?

        • I think seeing it as a game might be one of the best ways to look at it.

          If I may add some context to the Nietzsche quote I put in this morning:

          “In some remote corner of the universe, poured out and glittering in innumerable solar systems, there once was a star on which clever animals invented knowledge. (…) After nature had drawn a few breaths the star grew cold, and the clever animals had to die.

          On might invent such a fable and still not have illustrated sufficiently how wretched, how shadowy and flighty, how aimless and arbitrary, the human intellect appears in nature. There have been eternities when it did not exist; and when it is done for again, nothing will have happened.”

          Cosmic meaning: yes. Will it make any difference: no. So we might call it cosmic meaning in the minimalist sense. 🙂

  6. dimvisionary says:

    Excellent article!

    I take Mumonkan as saying “the map is not the territory.”

    If the further question is: “Does the territory exist outside the map?”, then my gut answer is yes. But somehow it seems as if the territory wanted a map and presto: human consciousness.

    • Thank you for your comment, dimvisionary! I think the Mumonkan can be interpreted in many different ways, each one as good as the other. If you say ‘the territory wanted a map’ I have a question associated with that: how could the territory want anything without a form of self-consciousness? It depends on how you look at the territory, I guess!

      • dimvisionary says:

        Exactly! Since every atom in your body is the product of a star and came directly from the coalescence of atoms called the earth… and since every calorie you have ever burned originated within the sun, is it accurate to describe your consciousness as “yours” or the territory’s? Ji ji mu ge. Is there a difference and is that difference only perception?

  7. dimvisionary says:

    Please allow me to add on to my comment to your excellent post. I did not mean to suggest that human consciousness is the only consciousness. It is only one variety, articulate and symbolic.

    Here’s a twin question to your own: If Nietzsche had written all of his writing’s and you had not read them, would they exist?

    • Thanks again! I see what you mean about consciousness.

      That’s a tough question. And it made me laugh. At first thought, I’d say Nietzsche’s writings would be out there, the way I know America to be there, even though I’ve never set foot on the continent. The Pyrrhonists (I once did an article on them) reserved judgement on all thoughts that didn’t spring forth from their own direct sense-experiences but in these cases I don’t do that. Nietzsche’s writings and America would be part of my frame of reference the same way memories are. Not something I could see, hear or touch at this very moment and therefore less important, but not like a unicorn either. Does that make any sense?

      • dimvisionary says:

        Yes, it makes sense, at least to me. Language and it’s communication can be so slippery.

        My last blog, on what I term The First Principle addresses this. I’m not trying to horn my own blog but I would appreciate your lively and skeptical approach! And it seems relevant to the current dialogue. Some things exist materially and some only exist in the human mind, as you eloquently pointed out by distinguishing physics from psychology. Differentiating the two can be confusing and revelatory.

        A Gary Larson part of my brain likes to imagine that the tree falling (absent of humans) did make a noise because a local squirrel who happened to speak tree distinctly heard it say, “Oh shit, I’m falling.”

        • I’ll read your blog on The First Principle and see what I come up with.

          Your point about ‘speaking tree’ is important, I think. We humans tend to forget our limitations when it comes to the many languages spoken around us! I had to look up Gary Larson and the first cartoon I saw was of an icebear eating an igloo (the footprints suggest there’s someone in it) and commenting: “I love this stuff – it’s crunchy on the outside and has a chewy centre!” I’m still chuckling!

  8. Dara says:

    Great stuff and great commentary. We are all such busy little bees! Thinking, thinking, thinking. This makes me question the nature of evidence. If evidence is mere perception does it become meaningless when I am not perceiving it? As usual, humans put themselves at the centre of the experience. Maybe trees ask themselves “Am I only erect because there are no humans to chop me down?” Or perhaps more analagous – “If a human dies in the city (and not my forest) will any tree hear him scream?”
    Perception is only conclusion based on evidence informed by received knowledge. How many children start off thinking they cannot be seen when they cover their eyes?

    I welcome your referencing of Nietzsche – it has been quite trendy to dismiss him because of the misappropriation of his ideas during WWII so it’s nice to come across a balanced fan.

    • Thank you for your comment, Dara. I’m also very impressed with the quality of the commentary on this one!
      I like your point about evidence. This would merit its own post if you ask me.

      We seem to ignore the perspective of the tree just because we don’t speak its language. That might be us grownups covering our eyes.

      As to you calling me a balanced fan of Nietzsche; it’s much worse than that I’m afraid. Just look at today’s article to get a glimpse of what I’m talking about.

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