1. The original formulation and variations
    Paradox of the heap  Variations 

2. Proposed resolutions
    Setting a fixed boundary  Unknowable boundaries (or epistemicism)  Supervaluationism  Truth gaps, gluts, and multi-valued logics  Hysteresis  Group consensus  Dropping transitivity of the relations involved 

3. See also

4. References

5. Bibliography

6. External links

The sorites paradox ({{IPAc-en|s|oʊ|'|r|aɪ|t|iː|z}};^[1] sometimes known as the paradox of the heap) is a paradox that arises from vague predicates.^[2] A typical formulation involves a heap of sand, from which grains are individually removed. Under the assumption that removing a single grain does not turn a heap into a non-heap, the paradox is to consider what happens when the process is repeated enough times: is a single remaining grain still a heap? If not, when did it change from a heap to a non-heap?^[3]

The original formulation and variations

Paradox of the heap

The word "sorites" derives from the Greek word for heap.^[4] The paradox is so named because of its original characterization, attributed to Eubulides of Miletus.^[5] The paradox goes as follows: consider a heap of sand from which grains are individually removed. One might construct the argument, using premises, as follows:^[3]

{{val|1000000|fmt=commas}} grains of sand is a heap of sand (Premise 1)

A heap of sand minus one grain is still a heap. (Premise 2)

Read (1995) observes that "the argument is itself a heap, or sorites, of steps of modus ponens":^[7]

{{val|1000000|fmt=commas}} grains is a heap.

If {{val|1000000|fmt=commas}} grains is a heap then {{val|999999|fmt=commas}} grains is a heap.

So {{val|999999|fmt=commas}} grains is a heap.

If {{val|999999|fmt=commas}} grains is a heap then {{val|999998|fmt=commas}} grains is a heap.

So {{val|999998|fmt=commas}} grains is a heap.

If ...

... So {{val|1}} grain is a heap.

Variations

Another formulation is to start with a grain of sand, which is clearly not a heap, and then assume that adding a single grain of sand to something that is not a heap does not turn it into a heap. Inductively, this process can be repeated as much as one wants without ever constructing a heap.^[2][3] A more natural formulation of this variant is to assume a set of colored chips exists such that two adjacent chips vary in color too little for human eyesight to be able to distinguish between them. Then by induction on this premise, humans would not be able to distinguish between any colors.^[2]

The removal of one drop from the ocean, will not make it 'not an ocean' (it is still an ocean), but since the volume of water in the ocean is finite, eventually, after enough removals, even a litre of water left is still an ocean.

This paradox can be reconstructed for a variety of predicates, for example, with "tall", "rich", "old", "blue", "bald", and so on. Bertrand Russell argued that all of natural language, even logical connectives, is vague; moreover, representations of propositions are vague.^[8]

Other similar paradoxes are:

• Argument of the beard^[9]
• The bald man paradox

Proposed resolutions

On the face of it, there are some ways to avoid this conclusion. One may object to the first premise by denying {{val|1000000|fmt=commas}} grains of sand makes a heap. But {{val|1000000|fmt=commas}} is just an arbitrarily large number, and the argument will go through with any such number. So the response must deny outright that there are such things as heaps. Peter Unger defends this solution.^[10] Alternatively, one may object to the second premise by stating that it is not true for all heaps of sand that removing one grain from it still makes a heap.{{citation needed|date=November 2016}}

Setting a fixed boundary

A common first response to the paradox is to call any set of grains that has more than a certain number of grains in it a heap. If one were to set the "fixed boundary" at, say, {{val|10000|fmt=commas}} grains then one would claim that for fewer than {{val|10000|fmt=commas}}, it is not a heap; for {{val|10000|fmt=commas}} or more, then it is a heap.^[11]

However, such solutions are unsatisfactory as there seems little significance to the difference between {{val|9999|fmt=commas}} grains and {{val|10000|fmt=commas}} grains. The boundary, wherever it may be set, remains as arbitrary and so its precision is misleading. It is objectionable on both philosophical and linguistic grounds: the former on account of its arbitrariness, and the latter on the ground that it is simply not how we use natural language.^[12]

A second response attempts to find a fixed boundary that reflects common usage of a term. For example, a dictionary may define a "heap" as "a collection of things thrown together so as to form an elevation."^[13] This requires there to be enough grains that some grains are supported by other grains. Thus, adding one grain atop a single layer produces a heap, and removing the last grain above the bottom layer destroys the heap.

Unknowable boundaries (or epistemicism)

Timothy Williamson^[14][15][16] and Roy Sorensen^[17] hold an approach that there are fixed boundaries but that they are necessarily unknowable.

Supervaluationism

As an example for a proposition about an irreferential singular term, consider the sentence "Pegasus likes licorice".

Since the name "Pegasus" fails to refer, no truth value can be assigned to the sentence; there is nothing in the myth that would justify any such assignment. However, there are some statements about "Pegasus" which have definite truth values nevertheless, such as "Pegasus likes licorice or Pegasus doesn't like licorice". This sentence is an instance of the tautology "", i.e. the valid schema " or not-". According to supervaluationism, it should be true regardless of whether or not its components have a truth value.

Similarly, "{{val|1000|fmt=commas}} grains of sand is a heap of sand" may be considered a border case having no truth value, but "{{val|1000|fmt=commas}} grains of sand is a heap of sand, or {{val|1000|fmt=commas}} grains of sand is not a heap of sand" should be true.

Precisely, let be a classical valuation defined on every atomic sentence of the language , and let be the number of distinct atomic sentences in . Then for every sentence , at most distinct classical valuations can exist. A supervaluation is a function from sentences to truth values such that, a sentence is super-true (i.e. ) if and only if for every classical valuation ; likewise for super-false. Otherwise, is undefined—i.e. exactly when there are two classical valuations and such that and .

For example, let be the formal translation of "Pegasus likes licorice". Then there are exactly two classical valuations and on , viz. and . So is neither super-true nor super-false. However, the tautology is evaluated to by every classical valuation; it is hence super-true. Similarly, the formalization of the above heap proposition is neither super-true nor super-false, but is super-true.

Truth gaps, gluts, and multi-valued logics

Another approach is to use a multi-valued logic. From this point of view, the problem is with the principle of bivalence: the sand is either a heap or is not a heap, without any shades of gray. Instead of two logical states, heap and not-heap, a three value system can be used, for example heap, indeterminate and not-heap. However, three valued systems do not truly resolve the paradox as there is still a dividing line between heap and indeterminate and also between indeterminate and not-heap. The third truth-value can be understood either as a truth-value gap or as a truth-value glut.^[22]

Alternatively, fuzzy logic offers a continuous spectrum of logical states represented in the unit interval of real numbers [0,1]—it is a many-valued logic with infinitely-many truth-values, and thus the sand moves smoothly from "definitely heap" to "definitely not heap", with shades in the intermediate region. Fuzzy hedges are used to divide the continuum into regions corresponding to classes like definitely heap, mostly heap, partly heap, slightly heap, and not heap.

^[23][24]Though the problem remains of where these borders occur; e.g. at what number of grains sand starts being 'definitely' a heap.

Hysteresis

Another approach, introduced by Raffman,^[25] is to use hysteresis, that is, knowledge of what the collection of sand started as. Equivalent amounts of sand may be called heaps or not based on how they got there. If a large heap (indisputably described as a heap) is slowly diminished, it preserves its "heap status" to a point, even as the actual amount of sand is reduced to a smaller number of grains. For example, suppose {{val|500}} grains is a pile and {{val|1000|fmt=commas}} grains is a heap. There will be an overlap for these states. So if one is reducing it from a heap to a pile, it is a heap going down until, say, {{val|750}}. At that point one would stop calling it a heap and start calling it a pile. But if one replaces one grain, it would not instantly turn back into a heap. When going up it would remain a pile until, say, {{val|900}} grains. The numbers picked are arbitrary; the point is, that the same amount can be either a heap or a pile depending on what it was before the change. A common use of hysteresis would be the thermostat for air conditioning: the AC is set at 77 °F and it then cools down to just below 77 °F, but does not turn on again instantly at 77.001 °F—it waits until almost 78 °F, to prevent instant change of state over and over again.^[26]

Group consensus

One can establish the meaning of the word "heap" by appealing to consensus. Williamson, in his epistemic solution to the paradox, assumes that the meaning of vague terms must be determined by group usage.^[27] The consensus approach typically claims that a collection of grains is as much a "heap" as the proportion of people in a group who believe it to be so. In other words, the probability that any collection is considered a heap is the expected value of the distribution of the group's views.

A group may decide that:

• One grain of sand on its own is not a heap.
• A large collection of grains of sand is a heap.

Between the two extremes, individual members of the group may disagree with each other over whether any particular collection can be labelled a "heap". The collection can then not be definitively claimed to be a "heap" or "not a heap". This can be considered an appeal to descriptive linguistics rather than prescriptive linguistics, as it resolves the issue of definition based on how the population uses natural language. Indeed, if a precise prescriptive definition of "heap" is available then the group consensus will always be unanimous and the paradox does not arise.

Dropping transitivity of the relations involved

In the above color example, the argument is tacitly based on considering the relation "for the human eye, color X is indistinguishable from Y" as an equivalence relation, in particular as transitive. To drop the transitivity assumption is a possibility to resolve the paradox.

Similarly, the paradox is based on considering the relation "for the human eye, color X looks more or equally red than Y" as a reflexive total ordering; again, dropping its transitivity resolves the paradox.

Instead, the relation between colors can be described as a quasitransitive relation, employing a concept introduced by microeconomist Amartya Sen in 1969.^[28]

The table shows a simple example, with color differences overdone for readability. A "Q" and a "T" indicates that the row's color looks more or equally red than column's color in the quasitransitive and the transitive version of the relation, respectively. In the quasitransitive version, e.g. the colors {{color|#f01000|f01000}} and {{color|#e02000|e02000}} are modelled as indistinguishable, since a "Q" appears in both their intersection cells. A "P" indicates the asymmetric part of the quasitransitive version.

To resolve the original heap variation of the paradox with this approach, the relation "X grains are more a heap than Y grains" should be considered quasitransitive rather than transitive.{{citation needed|date=December 2016}}{{clarify|date=December 2016|reason=How does it resolve?}}

See also

• Ambiguity
• Boiling frog
• Continuum fallacy
• I know it when I see it
• Ring species
• Ship of Theseus
• Slippery slope
• Straw that broke the camel's back

References

Bibliography

• {{Cite book |last=Barnes |first=J. |year=1982 |chapter=Medicine, Experience and Logic |editor1-last=Barnes |editor1-first=J. |editor2-last=Brunschwig |editor2-first=J. |editor3-last=Burnyeat |editor3-first=M. F. |editor4-last=Schofield |editor4-first=M. |title=Science and Speculation |location=Cambridge |publisher=Cambridge University Press |ref=harv |postscript=}}
• {{cite book |last=Black |first=Max |authorlink=Max Black |title=Margins of Precision |isbn=978-0-8014-0602-7 |year=1970 |publisher=Cornell University Press |location=Ithaca, NY}}
• {{cite book |last=Burns |first=Linda Claire |title=Vagueness: An Investigation into Natural Languages and the Sorites Paradox |isbn=978-0-7923-1489-9 |year=1991 |publisher=Kluwer Academic Publishers |location=Dordrecht}}
• {{Cite book | first=Myles |last=Burnyeat |authorlink=Myles Burnyeat |editor1-last=Schofield |editor1-first=M. |editor2-last=Nussbaum |editor2-first=M. C. |title=Language and Logos |year=1982 |chapter=15. Gods and heaps |location=Cambridge |publisher=Cambridge University Press |pages=[https://books.google.com/books?id=M8FjmaH–0V4C&pg=PA315 315–] |ref=harv |postscript=}}
• {{cite journal |last1=Collins |first1=Rory |title=On the Borders of Vagueness and the Vagueness of Borders |journal=Vassar College Journal of Philosophy |date=2018 |volume=5 |pages=30–44 |url=https://philosophy.vassar.edu/docs/2018-spring-VCJP%20Borders%20w%20CFP.pdf |accessdate=21 June 2018}}
• Damir D. Dzhafarov, The sorites paradox: a behavioral approach (with E. N. Dzhafarov), in J. Valsiner and L. Dudolph (eds.).
• {{cite book |last=Gerla |title=Fuzzy logic: Mathematical Tools for Approximate Reasoning |year=2001 |isbn=978-0-7923-6941-7 |publisher=Kluwer Academic Publishers |location=Dordrecht, Netherlands}}
• Kirk Ludwig & Greg Ray, "Vagueness and the Sorites Paradox", Philosophical Perspectives 16, 2002.
• {{cite conference |first1=Rick |last1=Nouwen |first2=Robert van |last2=Rooij |first3=Uli |last3=Sauerland |first4=Hans-Christian |last4=Schmitz |title=International Workshop on Vagueness in Communication (ViC; held as part of ESSLLI) |publisher=Springer |series=LNAI |volume=6517 |isbn=978-3-642-18445-1 |year=2009}}
• {{cite book|last=Sainsbury |first=R. M. |title=Paradoxes |year=2009 |publisher=Cambridge University Press |edition=3rd}}; Sect.3

External links

• {{cite SEP |url-id=sorites-paradox |title=Sorites Paradox}} by Dominic Hyde.

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