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T H E E N T H Y M E M E I N P O L I T I C A L A N D
J U D I C I A L A R G U M E N T A T I O N
G I O V A N N I D A M E L E

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Enthymeme ( ἐ νθύμημα)
(  ῶ μα τ ῆ ς πίστεως, Aristotle, Rhet. I, 1, 1354a)
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An argument with incomplete premises
[Richard Feldman, Reason and Argument]
An argument with an implicit premise or conclusion
[Donald C. Wilson, A guide to good reasoning]
An argument regarding probabilities and/or signs
[Aristotle, Rhetoric]

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 The enthymeme is an incomplete syllogism based on probabilities or signs

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 The enthymeme is an incomplete syllogism based on probabilities or signs
[Probabilitas consequentis]

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 The enthymeme is an incomplete syllogism based on probabilities or signs
[Probabilitas consequentis]

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 The enthymeme is an incomplete syllogism based on probabilities or signs
[Probabilitas consequentis]
The enthymeme is a
“deductively” valid argument (syllogism) that can be made explicit by adding a premise that is tacitly understood

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 The enthymeme is an incomplete syllogism based on probabilities or signs
[Probabilitas consequentis]
The enthymeme is a
“deductively” valid argument (syllogism) that can be made explicit by adding a premise that is tacitly understood

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 The enthymeme is an incomplete syllogism based on probabilities or signs
[Probabilitas consequentis]
The enthymeme is a
“deductively” valid argument (syllogism) that can be made explicit by adding a premise that is tacitly understood
The enthymeme is an argument based on eikos
[“eikotic argument”]:
•‘probability’
•‘plausibility’
•‘likelihood’

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 The enthymeme is an incomplete syllogism
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The most evident characteristic of the enthymeme is the shortened formulation
Some of the components of the argument need to be filled in
(as premises or conclusions)
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Needed assumptions:
 when the (missing) propositions in question are inserted, the argument becomes structurally correct (deductively valid)
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Used assumptions:
 propositions that, even not explicitly stated, are meant to be the part of the argument by the speaker
[Ennis (1982, 63-66)]

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 The enthymeme is an incomplete syllogism
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Filling in used assumptions it depends of an interpretation of what the speaker meant to say, in a given case.
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Straw man fallacy: a tactical move based on an attribution of an implicit premise or conclusion to a speaker’s argument that distorts the argument in order to make it easier to refute
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Used assumptions are “unstated reasons” based on common knowledge.
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Argumentum ad populum: (fallacious) appeal to popular opinion
[Van Eemeren and Grootendorst (1984, 1992)]

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 The enthymeme is an incomplete syllogism
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Filling in needed assumptions, with some logical syllogistic calculus, can be done mechanically and is not a difficult problem
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The result of the evaluation of the inference in an enthymeme is the finding of an additional true sentence from which (in combination with the stated premises) the conclusion follows logically.
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It seems to imply that an enthymeme’s unstated premise is the minimal sentence whose addition will produce an argument whose conclusion follows logically
[Anderson and Belnap (1961, p. 719)]

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The enthymeme is based on probabilities or signs
Topics: commonly used arguments
Two uses:
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Inventio
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The function of a topic is to help an arguer search around to find an argument he can use, by selecting from among the various topics, or commonly used type of arguments
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Guarantee
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The topic can be used to find the warrant needed to support the inference from the premises to the conclusion of a given argument
[Kienpointner, (1997) & Kienpointner (1992)]

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 The enthymeme is based on probabilities or signs
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Defeasible generalization
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Is a kind of warrant that could be used in a plausible inference.
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At least that hypothesis may be the best explanation of the given data. In law such an inference might have some “probative weight”, even though the inference is defeasible, and could easily be defeated by other evidence in a case

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 The enthymeme is based on probabilities or signs
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Defeasible generalization
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Plausible reasoning. It can be identified with what Peirce called abductive inference. It is a fallible form of argumentation. It requires input from the audience, or respondent, to whom the argument was supposedly directed.
 argument from precedent
 argument from consequences
 argument from analogy
 arguments based on signs: none of the arguments is deductively valid or inductively strong.

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 The enthymeme is based on probabilities or signs
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Defeasible generalization
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Peirce abduction:
 abductive inference / rhetorical argumentation: both are fallible, and both depend on commonly held assumptions about what is typical, or can normally be expected, in a kind of situation that is familiar to both a speaker and a hearer.

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 The enthymeme is based on probabilities or signs
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Defeasible generalization
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(C): If the sky is clouded over, it is likely to rain
[Aristotle, Rhet. 2.19.24 1393a6-7; Burnyeat (1994, p.
26)]
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(C’): If the barometer is high, it is likely not to rain
[Burnyeat (1994, p. 28)]

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 The judicial discursive structure seems to be much more enthymematic than syllogistic, among other aspects, because not all the used norms are revealed, many of them staying not only out of question but also hidden.
[Diciotti (2006)].
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Those implicit norms are not just presupposed as evident, but they are also uncertain.

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Subsumptive conception
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The objective of the interpretation is a safe, sure and correct conclusion: the decision.
Casuistic (sceptical) perspective
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A general norm does not produce the decision or even build the frame inside of which the interpreter acts. The norm just serves as a posterior justification for a choice already made before.

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American legal realism emphasizes the empirical, variable character of judicial decisions and their unarticulated, unspoken major premises.
[Oliver Wendell Holmes]
«It is clear that the general legal norms neither express what law really is, what courts decide from case to case, nor produce its possibilities».
[Karl Llewellyn]
The general norm is not previous, only its text. What the legislator does, including the original constitutional power, is to produce the legal or constitutional text, not the norm properly said.

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 The foundation of the juridical decisions are topoi, more ore less indefinite opinions.
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The so called “undetermined legal concepts”
 common good
 honest woman
 good faith
 administrative probity
 property
 credit
 indecent exposure

…

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 «The argumentative structure expressed by the enthymeme theory seems more capable to reveal, for example, that “scientific” pillars like the unity of the state legal order, the judge’s neutrality or the objectivity of the law constitute, in the long run, mere discursive strategies».
[Adeodato (1999)]
“Enthymeme theory”: in what sense?

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 Aristotle (Topics) adopts a casual, informal definition of the “syllogism” as a logos, a “reasoning” or “discourse”. In the same place, dialectical syllogising is defined as reasoning from doxa.
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If then, “syllogism” can be used in such a sense with reference to every day thought and discourse
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Enthymeme and syllogism, as rhetoric and dialectic, are related to each other, but the relation is one of systematic difference well as similarity.

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 Rhetoric takes care not only of what is persuasive, but also of what seems to be persuasive
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Rhetoric is driven to obtain immediate effects.

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 Aristotle’s inclusion of pathos and ethos among the enthymematic sources of persuasion (in Rhet. 2.2-17) suggests that he considers enthymemes «something more than an act of reason».
[Grimaldi (1982)]

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 As Aristotle is careful to note (Rhet. 1.1 [1355a]), the enthymeme and syllogism are not the same
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Tis in sullogismos tis is an alienans qualification. An enthymeme is not a kind of sullogismos, still less a kind of syllogism. It is a sullogismos of a kind and a demonstration of a kind, a deduction from which you cannot expect everything you would normally expect from a valid deductive argument
[ Probabilitas consequentiae ]

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References
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Adeodato, J.M. (1999): The Rhetorical Syllogism (Enthymeme) in Judicial Argumentation,
“International Journal for the Semiotics of Law”, 12, 135-152
Anderson, A.R. and Belnap, N.D. (1961): Enthymemes, The Journal of Philosophy, 58, 713-723
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Burnyeat, M.F. (1994): Enthymeme: Aristotle on the Logic of Persuasion, in D.J. Furley and A.
Nehemas (eds.), Aristotle’s Rhetoric: Philosophical Essays, Princeton, 3-55
Diciotti, E. (2006): Regola di riconoscimento, controversie giuridiche e retorica, in M. Manzin and P. Sommaggio (eds.), Interpretazione giuridica e retorica forense, Milano, 73-116
Ennis, R.H. (1982): Identifying Implicit Assumptions, “Synthese”, 51, 61-86
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Eemeren, F.H. van and Grootendorst, R. (1984): Speech acts in argumentative discussions,
Dordrecht
Eemeren, F.H. van and Grootendorst, R. (1992): Argumentation, Communication and Fallacies,
Hillsdale
Grimaldi, W. M. A. (1988): Aristotle, Rhetoric II. A Commentary, New York
Kienpointner, M. (1987): Towards a Typology of Argument Schemes, in van Eemeren et al. (eds.),
Argumentation: Across the Lines of Discipline, Dordrecht, 275-287
Kienpointner, M. (1992): Alltagslogik: Struktur und Funktion von Argumentationsmustern,
Stuttgart