Transcript PPT - ArgLab

The body of persuasion
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THE ENTHYMEME IN POLITICAL AND
JUDICIAL ARGUMENTATION
GIOVANNI DAMELE
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Enthymeme (ἐνθύμημα)
(ῶμα τῆς πίστεως, Aristotle, Rhet. I, 1, 1354a)
 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
 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)
Needed assumptions:
 when the (missing) propositions in question are inserted, the
argument becomes structurally correct (deductively valid)
 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
 Filling in used assumptions it depends of an interpretation of
what the speaker meant to say, in a given case.


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
Used assumptions are “unstated reasons” based on common
knowledge.

Argumentum ad populum: (fallacious) appeal to popular opinion
[Van Eemeren and Grootendorst (1984, 1992)]
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 The enthymeme is an incomplete syllogism
 Filling in needed assumptions, with some logical syllogistic
calculus, can be done mechanically and is not a difficult
problem

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.
 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:
 Inventio


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
Guarantee

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
 Defeasible generalization
Is a kind of warrant that could be used in a plausible inference.
 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
 Defeasible generalization

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
 Defeasible generalization
 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

Defeasible generalization

(C): If the sky is clouded over, it is likely to rain
[Aristotle, Rhet. 2.19.24 1393a6-7; Burnyeat (1994, p.
26)]

(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)].
 Those implicit norms are not just presupposed as
evident, but they are also uncertain.
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 Subsumptive conception
 The objective of the interpretation is a safe, sure and correct
conclusion: the decision.
 Casuistic (sceptical) perspective
 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.

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.

If then, “syllogism” can be used in such a sense with reference
to every day thought and discourse

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
 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

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
 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
 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
 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