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Logical Fallacies

Sorites Fallacy

The sorites fallacy occurs when one argues that because a continuum exists between two distinct categories, those categories cannot be truly distinguished, thus rendering the distinction meaningless. It is rooted in vague predicates and incremental changes, and it often leads to paradoxes about heaps, wealth, or moral status.

THE IDEA

66 Sorites Fallacy

Jack Bowen

The FDA can’t claim one product as natural while another is not, because one small change along the continuum of not‐natural to natural doesn’t matter: you can’t draw a line between something that’s “natural” and something that’s not. So therefore, nothing is natural.

Jane Doe

One commits the sorites fallacy (SF) when claiming that because a continuum exists between two distinct categories or states of affairs, then those categories cannot truly be asserted as distinct. The term sorites derives from the Greek word soros , meaning “heap.” While it can apply to more real‐world issues than heaps of sand, the fallacy is best understood in its original conception. Imagine seeing a collection of sand grains upon which you claim it to not constitute a heap of sand. (Maybe you refer to it as a mere pile ?) A friend then adds a grain of sand to the pile and asks whether it is now a heap. You respond with a universally acceptable claim:

If something isn’t a heap, then adding a single grain of sand doesn’t make it a heap.

And yet, if one does this enough – trillions of times, let’s say – then, clearly, the pile does become , at some point, a heap.

The term heap has a fully functioning usage in our language. While we may not need to agree, in this particular case, as to how many grains designate a heap – or a pile, mound, and so on – this should not render the term useless, concluding that heaps do not actually exist.

The paradox works the other way as well. Upon seeing an exceptionally large collection of sand grains, you deem it a heap of sand. Your friend meticulously removes one grain and asks if it is still a heap. You vehemently defend that it is. After your friend repeats the action a number of times, each time removing one grain and asking if it remains a heap, you retort:

If something is a heap, then subtracting a single grain of sand doesn’t cause it to cease being a heap.

And yet, we know that doing this enough times will render the collection of sand grains miniscule and, with just three grains remaining, clearly not a heap.

And thus arises the SF: heaps of sand exist. Such fallacious argumentation can apply to any situation involving minor incremental changes, such as a single penny in determining whether someone is rich or poor, or a single day, minute, or second in determining the moral status of a human being such as is the case in asserting when a fetus becomes a moral entity.

Imagine someone’s applying this to the abortion argument. Upon encountering an argument that a fetus at the time of the first trimester then becomes a full‐fledged moral person and, thus, cannot be terminated, the counter‐argument is given:

But one day (or minute, or second) after the first trimester doesn’t matter. Since one day doesn’t matter, then the second day shouldn’t matter either. And then, the day after that, and so on. So, since you can keep adding seconds, minutes, and days to your original position, then the fetus never becomes a moral entity.

In the case of a developing fetus, a continuum exists from conception (which itself is more of a process than an exact moment) to the time of birth. And so the fallacy can be applied both ways. On the one hand, as per above, if you think it’s permissible to kill a fertilized egg, then you must think it permissible to kill a human baby. And on the other, if you think it’s wrong to kill a newborn baby, then you must also agree it is wrong to kill a fertilized egg.

It’s important to recognize a key difference between developing heaps and developing humans. Adding grains of sand to heaps doesn’t affect any essential quality of a heap of sand. And yet, the growth of a human being does involve its developing what we might consider essential qualities. Throughout the stages in its development – that is, as days upon days transpire – the human fetus does change in important ways, developing organs – heart, brain, etc. – and other qualities such as sentience and viability, which we may find more relevant to an entity maintaining moral standing.

The flipside of this fallacy is that a word cannot maintain its meaning void of any criteria for proper usage. For example, if one were to use the word natural to include something like Yellow #5 based on the fact that Yellow #5 is made entirely from things “of nature” – that is, carbon, hydrogen, etc. – then it would render the term natural as meaningless. The term natural must have criteria for using the word correctly in order to maintain meaning. Imagine every item in a grocery store having the stamp, “All‐Natural”; it would fail to convey any meaning at all. Thus, with a vague term like natural , qualifications must be made. And, simply because incremental additions (or subtractions) in the definition of natural can be made between two items on opposite ends of the spectrum doesn’t mean that those two items are both “natural,” as per the SF.

In addition, the SF helps us to distinguish between vagueness and relativity. For example, the term rich is a relative term: a person in one part of the world may be considered rich there – that is, this person has considerably more money than most people living in that region – and yet, were this person to move to a more affluent part of the world, the person may be considered as not‐rich or even poor. That is to say, being rich has something to do with one’s place in society. But, within that, we can apply the SF to highlight the vagueness of the term. If a person in a specific culture is considered rich, then upon discovering he lost a penny, we would not then deem him as not‐rich. Yet, were he to lose a penny repeatedly, it’s certainly feasible that he would become not‐rich. Were one to claim that no difference exists between rich and poor based on the “losing a penny” defense, one would be committing the SF.

Recognizing the SF is helpful, on the one hand, in highlighting the vagueness of our linguistic constructs and categorical thinking. In a sense, it serves as a reminder of the inherent problem of our natural inclination to think categorically: in our habit of mind that the world fits into and abides by our human‐made categories, when it fails to do so, we should not be alarmed but should, instead, recognize this problem of language to begin with. But it also serves to remind us that simply because of the vagueness of categories, we shouldn’t render these categories as non‐existent or vacuous.

When to use it

  • Law: Determining when a person becomes an adult based on age increments – e.g., is there a meaningful difference between being 17 years 364 days old and 18 years old?

  • Business: Defining 'sustainable' products – incremental improvements in environmental impact may lead to the fallacy if one argues that no single improvement makes a product sustainable, thus nothing is sustainable.

  • Health: Categorizing obesity based on small weight changes – a person gaining a pound does not typically change their weight status, but repeated gain does; arguing that there is no distinction between obese and non-obese based on incremental changes is fallacious.

  • Everyday: Deciding when a collection of items becomes 'clutter' – adding one item at a time to a space may never seem to create clutter, but eventually it does; the sorites fallacy arises if one claims clutter does not exist because of gradual accumulation.

FROM THEORY TO EVERYDAY LIFE

In practice

01

Heap of Sand

Starting with a pile that is clearly not a heap, adding one grain at a time never seems to create a heap, yet after many additions it becomes a heap. Conversely, starting with a heap and removing one grain never seems to stop it being a heap, yet eventually it is not. The paradox arises from a vague predicate: what counts as a heap?

02

Rich vs. Poor

A person is considered rich in a given society. If they lose a penny, they are still rich. But losing pennies repeatedly would eventually make them not rich. Arguing that there is no real difference between rich and poor because incremental losses don't matter commits the sorites fallacy.

03

Abortion Argument

If a fetus becomes a moral person at the first trimester, then one day after that shouldn't matter, so by extension no day matters, leading to the conclusion that the fetus never becomes a moral entity. This fallacy can be applied both ways, equating fertilized eggs and newborns.

04

Natural vs. Not-Natural (FDA Example)

The FDA cannot distinguish between natural and not-natural products because any small change along the continuum doesn't matter, so nothing is natural. However, this ignores that the term 'natural' requires criteria to retain meaning; the sorites fallacy invalidates the argument.

✳

A MOMENT TO REFLECT

Put it to work.

  1. Think of a time when you argued that because gradual changes don't matter, there is no real difference between two categories (e.g., 'clean' and 'dirty', 'healthy' and 'unhealthy'). How might the sorites fallacy apply to your reasoning?

  2. How can we define boundaries for vague terms like 'heap', 'rich', or 'natural' without falling into the sorites fallacy? What criteria could make these terms meaningful?

  3. Consider the abortion debate. How might recognizing the sorites fallacy change the way you frame arguments about when a fetus attains moral standing?

CONTINUE THE CONVERSATION

Source texts

  • Bad Arguments 100 of the Most Important Fallacies in Western Philosophy (Steven Barbone, Michael Bruce)
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