Walton Chap. 7 “Enthymemes”
Many arguments having missing claims.
When you are dealing directly with the proposer Michael Gilbert has suggested a method to ascertain the missing claims.
However, it is often the case that the proposer of the arguments you are dealing with is not present.
1. The Tradition of Textbooks (pp. 221-226)
Historically enthymemes have been taken as incomplete syllogisms – first order major premise missing, second order minor premise missing, third order – conclusion omitted.
A sorites is two syllogisms linked together with the conclusion of the first serving as a premise of the second. The first is called the prosyllogism and the second the episyllogism. When the prosyllogism is an enthymeme the whole argument is called an epicheirema.
More recent accounts have taken any argument with missing claims as an enthymeme.
2. The Aristotelian Enthymeme (pp. 226-230)
For Aristotle an enthymeme was a syllogism from properties or signs. The major premise in these arguments could be either a universal or a statistical generalization.
Consequently, for Aristotle not all syllogisms are deductive and Aristotle’s conception of enthymeme is quite different from that found in standard textbooks.
3. The Question of Terminology (pp.230-233)
Should we go back to the original Aristotelian meaning, or stick with the corrupted one, given that it now so well established?
4. Types of Basis for the Enthymeme (pp. 233-235)
One basis for an enthymeme is a premise that does not need to be stated explicitly because it is general knowledge shared by the speaker and hearer.
Another basis for the ethymeme is custom, habit, or normal way of doing something known to the speaker and hearer, but which can be inferred to be such by a wider audience.
In some cases a non-explicit premise supplies a conceptual link that holds a chain of argumentation together. This can occur when a non-explicit premise provides a definition or a necessary link in practical reasoning between goals and means.
5. Innuendo and Implicature (pp. 235-237)
Another basis for enthymemes is innuendo, where the conclusion of an argument is not explicitly asserted, but only suggested by means of implicature. Letting the audience draw the conclusion can have a rhetorical effect or provide plausible deniability.
There is also a contextual type of enthymeme which has its basis in the conversation exchange between two parties taking part.
6. The Dangers of Deductivism (pp. 237-241)
Thomas teaches his students two separate techniques for enthymemes. One is to confine the argument to premises and conclusions that were believed or intended by the arguer. The second is to put in whatever missing assumptions are needed to make the argument deductively valid.
Arguments are used that are inherently inconclusive because they are used in a context of balance of considerations. On this view adding premises to an argument to make it correct or successful does not require making it deductively valid.
A crucial first step is the determination of the type of argument in a particular case. Arguments could be deductive, inductive or presumptive.
7. The ‘Straw Man’ Fallacy (pp. 241-245)
The ‘straw man fallacy’ is committed where the proponent (respondent) in a disputes misrepresents the position of The respondent (proponent), imputing to him a position that is implausible and easy to refute, and then goes on to argue against the position as though it really were his.
Analyzing and evaluating an allegation of ‘straw man’ fallacy is a problem of determining what the commitments of the arguer are. The type of dialogue and the past record of what the arguer has said can be used.
8. Argumentation Schemes (pp. 245-248)
An important tool for the analysis of enthymeme is the argumentation schema. An argument schema enables one to identify and evaluate arguments in ordinary discourse. A structure is provided by indicating roles that premises play and a set of evaluation questions for that type of argumentation.
Some types of argument schema are: (1) argument from sign; (2) argument from example; (3) argument from verbal classification; (4) argument from commitment and many more. (see pp. 245-246)
9. The Two Levels: Need and Use (pp. 248-252)
According to Ennis used assumptions are unstated reasons that we look for ‘when we are engaged in understanding someone.’ A needed assumption is something an argument needs in order to be as good an argument as it can be.
Determining needed assumptions is easier than determining used assumptions.
Bases for bases for determining non-explicitly used premises include:
(1) General shared knowledge
(2) The position of the proponent.
(3) Custom, habit, or normal ways of doing something.
(4) Conceptual links holding an argument together.
(5) Non-explicit premises of practical reasoning.
(6) Innuendo
10. Incompleteness (pp. 252-255)
Part of the exercise of identifying arguments should be presenting the textual and contextual evidence in favor of a particular identification of the premises and conclusion. This is not to rule out conditional evaluations of arguments.