This is a classic thing to consider (a question that may better be considered as a sort of infallible conjecture):
If a tree falls and no living thing with the ability to hear it fall hears it, did it actually make a sound?
Well, I’ll say yes! [yes it does make a sound] But it was a sound that no member of the fauna class heard. It is important to remember that sound is noise traveling along airwaves. The energy released from the falling of a tree would thus have created a sound (albeit a sound that no known listening device was around to hear).
As Wikipedia (2019) reveals, the magazine Scientific American corroborated the technical aspect of this question, while leaving out the philosophic side, “sound is vibration, transmitted to our senses through the mechanism of the ear, and recognised as sound only at our nerve centers. The falling of the tree or any other disturbance will produce vibration of the air.”
We could say then that “sound” is something within human experience. Outside of this it’s just vibrations in the air. Indeed, many argue (see, e.g., The Guardian, n.d.) that the definition of a sound is its detection, rather than the physical phenomenon.
Consider this, once we develop an instrument that can detect vibrations we couldn’t otherwise hear, a previously ‘non-existent’ sound comes into being.
So, if someone is there to hear the rapid movement of particles we can say it makes a sound, if no human is there to hear it fall, the fall will still cause the rapid movement of particles [i.e., what humans term: “sound”] but it will be one that falls on deaf ears (however! the hedgehog and the fox may/may not have been there to hear).*]
Scientifically-speaking, sound is sound and it is not contingent on humankind being around to interpret it. We are oh so anthropocentric aren’t we!
This question of the falling tree is really considering another question, do things that happen outside of our senses actually happen…
Full many a flower is born to blush unseen, And waste its sweetness on the desert air.
— Thomas Gray (English poet, 1716-1771)
In a poetic way, Gray is saying how many beautiful flowers bloomed without every being seen by a human’s eyes. We can’t know for sure that these beautiful flowers lived and died (because we or nobody else saw their rise and fall) but our instinct and knowledge of flora would lead us to assume that yes such beautiful blossomings happen irrespective of if we are there to see them or not.
The truth of the matter is this, thequestion of the tree falling out of earshot is really designed to hint to a more profound ethical question: if we are unaware of somebody’s suffering, does their suffering exist? (for us no, for them [and other’s who’ve guessed/been told] yes). It relates to the ideas of immaterialism proposed by George Berkeley some 300 years ago, who argued that the only things that exist are ideas and the human mind that is having/holding those ideas (BBC, 2015).
Subjective idealism | metaphysics | ‘only minds and mental contents exist’
Berkeley, in his book, A Treatise Concerning the Principles of Human Knowledge (1710), argues that, “But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park […] and nobody by to perceive them. […] The objects of sense exist only when they are perceived; the trees therefore are in the garden […] no longer than while there is somebody by to perceive them.”
Metaphysics is the branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter, between substance and attribute, and between possibility and actuality.
Metaphysics studies questions related to what it is for something to exist and what types of existence there are. Metaphysics seeks to answer, in an abstract and fully general manner, these two questions:
- What is there?
- What is it like?
From terrestrial to lunar
Albert Einstein is reported to have asked a fellow physicist Niels Bohr whether he realistically believed that ‘the moon does not exist if nobody is looking at it.’ To this Bohr replied that however hard one may try, they would not be able to prove that it does. This is, according to Mendis (2009) a fine example of an infallible conjecture (i.e., it cannot be either proved or disproved; sound familiar? “Timber!” cried the mute lumberjack).
* “The fox knows many things, but the hedgehog knows one big thing.” This ancient Greek aphorism, preserved in a fragment from the poet Archilochus, describes a thesis put forward by Isaiah Berlin regarding the philosophy of history. Although there have been many interpretations of the aphorism, Berlin uses it to mark a fundamental distinction between human beings who are fascinated by the infinite variety of things and those who relate everything to a central, all-embracing system.
Berlin’s extraordinary essay offers profound insights about Tolstoy, historical understanding, and human psychology (Kobo, 2019). According to Berlin, humans can be divided into two categories: hedgehogs, who view the world through the lens of a single defining idea (he cites: Plato, Dante Alighieri, Hegel, Nietzsche and Proust), and foxes, who draw on a wide variety of experiences and for whom the world cannot be summed up into a single idea (he cites: Aristotle, Desiderius Erasmus, William Shakespeare, and James Joyce) (Wikipedia, 2019b).
BBC (2015). A history of Ideas. British Broadcasting Corporation. Retrieved, bbc.co.uk/programmes/p02yq1b9
Kobo (2019). The Hedgehog and the Fox. Kobo
Mendis, M. (2009). Of Trees Falling in the Forest, on the anthropocentrism of philosophy. Big Think. Retrieved, bigthink.com/of-trees-falling
Steed, E. (2018, 25 June). Philosophy Illustrated. The New Yorker.
The Guardian (n.d.) Ethical Conundrums. The Guardian.
Wikipedia (2019a). If a tree falls in a forest. Wikipedia. Retrieved, wikipedia.org/wiki/
Wikipedia (2019b). The Hedgehog and the Fox. Wikipedia. Retrieved, wikipedia.org/wiki/