Definition and Examples of Sorites in Rhetoric

In logic, sorites is a chain of categorical syllogisms or enthymemes in which the intermediate conclusions have been omitted. Plural: sorites. Adjective: soritical. Also known as chain argument, climbing argument, little-by-little argument, and polysyllogism.

In Shakespeare's Use of the Arts of Language (1947), Sister Miriam Joseph notes that a sorites "normally involves repetition of the last word of each sentence or clause at the beginning of the next, a figure which the rhetoricians called climax or gradation, because it marks the degrees or steps in the argument."

• Etymology: From the Greek, "heap​
• Pronunciation: suh-RITE-eez

Examples and Observations

"Here is an example [of sorites]:

All bloodhounds are dogs.
All dogs are mammals.
No fish are mammals.
Therefore, no fish are bloodhounds.

The first two premises validly imply the intermediate conclusion 'All bloodhounds are mammals.' If this intermediate conclusion is then treated as a premise and put together with the third premise, the final conclusion follows validly. The sorites is thus composed of two valid categorical syllogisms and is therefore valid. The rule in evaluating a sorites is based on the idea that a chain is only as strong as its weakest link. If any of the component syllogisms in a sorites is invalid, the entire sorites is invalid."
(Patrick J. Hurley, A Concise Introduction to Logic, 11th ed. Wadsworth, 2012)
 

"St. Paul uses a causal sorites in the form of a gradatio when he wants to show the interlocking consequences that follow from a falsification of Christ's resurrection: 'Now if Christ be preached that He rose from the dead, how say some among you that there is no resurrection from the dead? But if there be no resurrection from the dead, then is Christ not risen: and if Christ be not risen, then is our teaching vain, and [if our preaching is vain] your faith is also vain" (I Cor. 15:12-14).

"We might unfold this sorites into the following syllogisms: 1. Christ was dead / The dead never rise / Therefore Christ did not rise; 2. That Christ did rise is not true / We preach that Christ is risen / Therefore we preach what is not true. 3. Preaching what is not true is preaching in vain / We preach what is not true / Therefore we preach in vain. 4. Our preaching is vain / Your faith comes from our preaching / Therefore your faith is vain. St. Paul, of course, made his premises hypothetical to show their disastrous consequences and then to contradict them firmly: 'But in fact Christ has been raised from the dead' (I Cor. 15:20)."
(Jeanne Fahnestock, Rhetorical Figures in Science. Oxford University Press, 1999)
 

The Sorites Paradox

"While the sorites conundrum can be presented as a series of puzzling questions it can be, and was, presented as a paradoxical argument having logical structure. The following argument form of the sorites was common:

1 grain of wheat does not make a heap.
If 1 grain of wheat does not make a heap then 2 grains of wheat do not.
If 2 grains of wheat do not make a heap then 3 grains do not.
.
.
.
_____
∴ 10,000 grains of wheat do not make a heap.

The argument certainly seems to be valid, employing only modus ponens and cut (enabling the chaining together of each sub-argument involving a single modus ponens inference.) These rules of inference are endorsed by both Stoic logic and modern classical logic, amongst others.

"Moreover its premises appear true. . . .

"The difference of one grain would seem to be too small to make any difference to the application of the predicate; it is a difference so negligible as to make no apparent difference to the truth-values of the respective antecedents and consequents. Yet the conclusion seems false."
(Dominic Hyde, "The Sorites Paradox." Vagueness: A Guide, ed. by Giuseppina Ronzitti. Springer, 2011)​

"The Sad Sorites," by Maid Marion​​

The Sorites looked at the Premiss
With a tear in his wistful eye,
And softly whispered a Major Term
To a Fallacy standing by.

O sweet it were to wander
Along the sad sea sand,
With a coyly blushing Predicate
Clasping thy willing hand!

O happy are the Mood and Tense,
If such indeed there be,
Who thus Per Accidens may roam
Beside the briny sea.

Where never Connotation comes,
Nor Denotation e'en.
Where Enthymemes are things unknown,
Dilemmas never seen.

Or where the tree of Porphyry
Bears stately branches high,
While far away we dimly see
A Paradox pass by.

Perchance a Syllogism comes,
In haste we see it fly
Hither, where peacefully it rests
Nor fears Dichotomy.

Ah! would such joys were mine! Alas
Empiric they must be,
Till hand in hand both Mood and Tense
Are joined thus lovingly.
(The Shotover Papers, Or, Echoes from Oxford, October 31, 1874)