Of missing trees, teapots, wallets and unicorns

The question “If a tree fell in a forest but no one saw or heard it fall, did it fall?” is a philosophical thought experiment that explores the nature of reality and our perception of it. I approach this problem from the angle of logic and reasoning:

1. Causality: According to the laws of physics, if a tree is subjected to sufficient forces (e.g., strong winds, decay, or a chainsaw), it will fall regardless of whether anyone is there to observe it. The cause (forces acting on the tree) leads to the effect (the tree falling) independently of human perception.
2. Objective reality: The world exists independently of our perception of it. Just because we do not perceive something does not mean it does not happen. For example, the Earth was orbiting the Sun long before humans were around to observe it.
3. Empirical evidence: If someone were to come across the fallen tree after the event, they could infer that it had fallen based on the evidence (the tree lying on the ground, disturbed soil, etc.). This suggests that the tree’s falling is an objective event that can be verified through observation, even if the actual moment of falling was not witnessed.
4. Consistency: If we were to assume that unobserved events do not occur, it would lead to logical inconsistencies. For instance, we could not explain the existence of fossil records, as no one directly observed those organisms living millions of years ago.
5. Occam’s Razor: This principle states that the simplest explanation is often the most likely one. In this case, the simplest explanation is that the tree fell, even if no one observed it, rather than proposing that reality is dependent on human perception.

Based on these logical arguments, some would argue that it is reasonable to conclude that the tree did fall, even if no one saw or heard it. The falling of the tree is an objective event that occurs independently of human perception, and its occurrence can be inferred through evidence and reasoning. But read on – as it is not that simple.

The flaw

My reasoning is that the assertion itself is flawed. Whilst trees may fall in forests – and that’s undeniable – the issue is that the assertion assumed that someone had knowledge based on evidence that ‘a tree’ fell. If no one saw or heard it fall then the assertion is false. It is ‘a tree’ in the singular. The generality of trees falling in forests and I not seeing them, is a separate matter. I can infer that trees fall in forests but in the grand scheme of things I could have no real knowledge of all trees falling in forests.

The problem with the assertion “If a tree fell in a forest but no one saw or heard it fall, did it fall?” is that it assumes knowledge of a specific event (a single tree falling) without any evidence to support it.

The above reasoning highlights the difference between the general concept of trees falling in forests and the specific claim about a single tree falling. While we can infer that trees do fall in forests based on our understanding of the world, claiming that a specific tree fell without any evidence is problematic.

By extension ‘if trees fell in forests and no one heard or saw them fall’, is equally erroneous i.e. no one saw or heard them and there is no evidence.

Teapot

The situation is similar to someone asserting that there is a teapot orbiting the earth but no one on earth can have the means to see it orbiting.

The teapot analogy is a famous philosophical thought experiment known as Russell’s teapot, proposed by Bertrand Russell. It illustrates that the burden of proof lies with the person making an unfalsifiable claim, not with others to disprove it.

In the case of the falling tree, if someone were to assert that a specific tree fell without any evidence, it would be logically unsound to accept that claim as true.

However, if the assertion were modified to “Trees fall in forests, even if no one sees or hears them,” it would be a more defensible statement. This shifts the focus from a specific unverifiable event to a general principle that aligns with our understanding of the world.

Evidence

Some say that the lack of evidence does not automatically make the claim false, but it does make it unjustified. The assertion that a tree fell but no one witnessed it fall, is self-defeating because the person making the assertion cannot assert that for which a) they have not witnessed and/nor b) the lack of evidence.

Breaking it down:

1. The assertion is made by a person who claims that a specific tree fell.
2. However, the same assertion also states that no one witnessed the tree falling.
3. If no one witnessed the tree falling, then there is no evidence to support the claim that the specific tree fell.
4. Without evidence, the person making the assertion cannot logically claim that the tree fell.

In essence, the person making the assertion is claiming knowledge of an event for which they admittedly have no evidence. This is a logical fallacy known as “begging the question” or “circular reasoning,” where the premise of an argument (that a tree fell) is assumed in the conclusion (even though no one witnessed it).

Absence of evidence

Some say that the lack of evidence for the specific tree falling does not necessarily mean it did not happen, but that it does mean the assertion cannot be logically made or accepted as true.

I would go further to assert that it did not happen that ‘a tree’ fell based on the very nature of the self-defeating assertion. There is the old conundrum of ‘absence of evidence does not mean evidence of absence’.

If I claim that I lost my wallet with £100 in it but there is no evidence that I had a wallet or £100 in it, how would anyone accept that I actually lost such a wallet? Others can go on my word. But then I could be lying (as thought experiment) and then others would believe the lie on no evidence of the existence of a wallet or the cash. Should a search party go looking for my wallet at a certain lonely spot in the woods and not find the wallet. Then they may say ‘There is no evidence of a wallet here – we did not find it.‘ But assuming I was lying, they would have believed the wallet was lost – which is a separate matter to the existence of a wallet. If I then wanted to be mischievous (in this thought experiment), I could then argue (whilst lying) that ‘not because you all did not find the wallet means it is not lost.’

The wallet analogy highlights the importance of distinguishing between the actual existence of an object or event and the belief in its existence based on someone’s word. If I claimed to have lost a wallet with £100 in it, but there was no evidence of me ever having such a wallet, it would be unreasonable for others to accept my claim as true without question.

The search party’s failure to find the wallet does not prove its existence or non-existence. It simply means that there is no evidence to support my claim. The search party’s belief in the existence of the wallet based on my word is a separate matter from the actual existence of the wallet at some point in time.

The hypothetical mischievous argument, “not because you all did not find the wallet means it is not lost,” is a logical fallacy known as “arguing from ignorance” or “argumentum ad ignorantiam.” This fallacy asserts that a proposition must be true because it has not been proven false or false because it has not been proven true.

The phrase “absence of evidence is not evidence of absence” is often used to suggest that a lack of evidence for something does not necessarily mean it does not exist. However, when used improperly, it can lead to the same logical fallacy as argumentum ad ignorantiam.

Unicorns and extraterrestrial life

Consider the following examples:

1. “There is no evidence that unicorns exist, but that doesn’t mean they don’t exist somewhere in the universe.” This statement uses the absence of evidence to suggest the possibility of existence, which is a form of argumentum ad ignorantiam.
2. “We have no evidence of intelligent extraterrestrial life, but that doesn’t mean it doesn’t exist.” While this statement may seem reasonable, it still relies on the lack of evidence to suggest the possibility of existence.

In both cases, the absence of evidence is used to support the possibility of existence without providing any positive evidence for the claim.

However, there are situations where the phrase “absence of evidence is not evidence of absence” can be used appropriately. For example, in scientific research, a lack of evidence for a hypothesis does not necessarily mean the hypothesis is false; it simply means that more research is needed to gather evidence either supporting or refuting the hypothesis. But note that hypothesis is not fact.

The key difference lies in the context and the way the statement is used. When used to suggest the possibility of existence without any supporting evidence, it falls into the argumentum ad ignorantiam fallacy. When used to encourage further investigation or to acknowledge the limitations of current knowledge, it can be a valid statement.

In the case of the falling tree or the lost wallet, using the absence of evidence to claim that the tree fell or that the wallet exists would examples of the argumentum ad ignorantiam fallacy.

Existence

The existence of a thing, be it a tree or a wallet, requires evidence of its existence before any claims can be made about its state, such as falling or being lost.

In philosophical terms, this is closely related to the concept of ontology, which is the study of the nature of being, existence, and reality. For something to be considered as existing, there must be some form of evidence proving its existence.

In the case of the falling tree, to claim that a specific tree fell, one would first need to establish the existence of that particular tree. This could be done through various forms of evidence, such as visual observation, photographs, or satellite imagery showing the tree standing at an earlier point in time.

Similarly, in the lost wallet example, to claim that a wallet was lost, one would need to provide evidence that the wallet existed in the first place. This could include receipts showing the purchase of the wallet, witnesses who saw the wallet, or photographs of the wallet. I fully understand that in ordinary life we trust people to be telling the truth and we do rely on their word. But this exploration is about raw logic.

Without establishing the existence of the tree or the wallet, any claims about their state (falling or being lost) are baseless and fall into the realm of logical fallacies, such as argumentum ad ignorantiam or begging the question.

The point emphasises the importance of grounding claims in evidence and the necessity of establishing the existence of an object or entity before making any assertions about its properties or state. This is a fundamental principle in logic, philosophy, and scientific reasoning, which helps to avoid fallacious arguments and unsupported claims.

In the absence of any evidence for the existence of a specific tree or wallet, it is not logically sound to conclude that they could exist. The proper conclusion would be that we have no evidence to support their existence.

This ties into the philosophical concept of the burden of proof, which states that the person making a claim is responsible for providing evidence to support it. If someone claims that a specific tree exists or that they owned a particular wallet, they are obligated to provide evidence for their claim.

In the absence of such evidence, the default position is not to assume the possibility of existence but rather to conclude that there is no reason to believe in the existence of the tree or the wallet.

This is in line with the principle of Occam’s Razor, which suggests that when presented with competing hypotheses, one should select the explanation that makes the fewest assumptions. In this case, assuming the existence of a tree or a wallet without any evidence would be making an unnecessary assumption.

Moreover, accepting the possibility of existence without evidence can lead to a slippery slope fallacy, where one could claim the potential existence of anything without any basis in reality.

Therefore, in the absence of evidence for the existence of a specific tree or wallet, the most rational and logically sound conclusion is to state that we have no evidence to support their existence, rather than entertaining the possibility that they could exist.

Non-existence

The idea that the absence of evidence for the existence of a thing can be considered evidence of its absence is a logical step forward from that above.

This concept is closely related to the philosophical principle known as the “negation of existence” or “negative proof.” In essence, it suggests that if there is no evidence for the existence of something, despite thorough investigation or the expectation of evidence if it did exist, then that absence of evidence can be seen as evidence of its non-existence.

Applying this to previous examples:

1. If we were to thoroughly search a specific area of a forest and find no evidence of a particular tree, despite having the means and expectation to find evidence if it did exist, then the absence of evidence could be considered evidence that the tree does not exist in that location. I’m not to embark on conspiracy theories that aliens snatched the tree clean off the earth after it fell.
2. If someone claimed to have lost a wallet but could not provide any evidence of ever owning such a wallet, despite the expectation that there would be evidence if the wallet did exist (receipts, photographs, witnesses), then the absence of evidence to prove its existence before going missing, could be seen as evidence that the wallet never existed.

This principle is often used in scientific reasoning, where the absence of expected evidence can lead to the rejection of a hypothesis. For example, if a scientific theory predicts a certain observable phenomenon, but repeated experiments fail to provide any evidence of that phenomenon, the absence of evidence can be considered evidence that the theory is incorrect.

However, it is important to note that the strength of the “absence of evidence” as “evidence of absence” depends on the thoroughness of the investigation and the likelihood of finding evidence if the thing in question did exist. The more comprehensive the search for evidence and the higher the expectation of finding evidence if it existed, the stronger the case for absence.

Fishing expedition

I can’t spend my time doing thorough investigations for any sort of wild assertion that does not offer up evidence. The people who make assertions are burdened to provide their own evidence. Else they’re sending me on a fishing expedition to disprove them in effect.

It is not my responsibility to invest time and effort in investigating every claim that is made without evidence.

This principle is known as “onus probandi” or “the burden of proof” in philosophy and logic. It states that the person making a positive claim is responsible for providing evidence to support their assertion. It is not the responsibility of others to disprove the claim.

If someone were to make a wild assertion without providing any evidence, such as claiming that invisible dragons exist or that they have a magic wand that can turn lead into gold, it would be unreasonable to expect others to spend their time and resources attempting to disprove these claims.

Attempting to disprove unsubstantiated claims would indeed be like going on a fishing expedition, wasting time and effort on a fruitless endeavor. It would be an endless task, as anyone could make countless baseless assertions that would require investigation.

Moreover, attempting to disprove a claim without evidence can sometimes be an impossible task, as it is often impossible to prove a negative. For example, one cannot prove that invisible dragons do not exist, as their invisibility makes it impossible to detect them. I shall not be going in search of dragon droppings!

Therefore, the burden of proof remains with the person making the assertion. If they cannot provide evidence to support their claim, it is not the responsibility of others to investigate or disprove it. The default position in such cases is to reject the claim until sufficient evidence is presented.

Conclusion

The age-old philosophical conundrum, “If a tree fell in a forest but no one saw or heard it fall, did it fall?” has sparked countless debates and discussions over the years. At its core, this thought experiment challenges our understanding of reality and the nature of existence. Through a careful examination of logic and reasoning, we can unravel the complexities of this question and arrive at a clear conclusion.

The assertion that a tree fell in the forest without anyone witnessing it is inherently self-defeating. It relies on the assumption that someone has knowledge of the event without any evidence to support it. The absence of evidence for the tree’s fall does not necessarily prove that it did not happen, but it does render the assertion logically unsound. Just as claiming the existence of a lost wallet without any proof is unjustified, asserting the fall of a specific tree without evidence is equally fallacious. The burden of proof lies with the person making the claim, and without meeting that burden, the assertion cannot be accepted as true.

Furthermore, the absence of evidence for the existence of a thing can be considered evidence of its absence, particularly when there is a reasonable expectation of evidence if the thing did exist. If a thorough search for a specific tree in a forest yields no evidence of its existence, despite the expectation of finding such evidence, it is logical to conclude that the tree does not exist in that location. However, it is crucial to recognize that the strength of this conclusion depends on the thoroughness of the investigation and the likelihood of discovering evidence if the thing in question did exist. Ultimately, the onus of providing evidence falls on the person making the assertion. It is not the responsibility of others to disprove baseless claims or to go fishing for evidence.