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| I. Historical Considerations. |
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A. After 2,000 years the standard treatment of fallacies remain much the same as the thirteen
fallacies pointed out by Aristotle in his Sophistical Refutations. |
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1. What is a sophist? (Note the word
"philosophy" and "sophomore.") Originally, a sophist
was a wise of learned person, one who engaged in the pursuit or communication of
knowledge. Now, a sophist is one who makes use of fallacious arguments--a specious
reasoner. |
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2. Some logicians, e.g., Bacon and Locke,
dropped the treatment of informal fallacies because logic is concerned with correct
reasoning only. |
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3. Yet, unless we are aware of some of the
mistakes that are likely to be made, i.e., unless we know what to avoid, we cannot
reason correctly. |
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B. No one is particularly satisfied with the
traditional treatment of fallacies--it is too unsystematic. Nevertheless, there seems to
be no way to give a systematic treatment of fallacies. |
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1. De Morgan writes in his Formal Logic
(276): "There is no such thing as classification of the ways men arrive at error: it
is much to be doubted whether there ever can be." |
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2, Joseph says in his Introduction to Logic
(569): "Truth may have its norm, but error is infinite in its aberrations, and they
cannot be digested in any classification." |
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3. There is no theory of fallacy except by
negative definition. |
| II. Even though there is no standard treatment, fallacies in
this course will be grouped as follows. |
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A. First, what is a fallacy? In general, it is
some form of deceptive reasoning. |
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1. A fallacy, then, is an argument which seems
to be valid, but is not really so. |
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2. Unfortunately, this is a psychological
definition. What counts as something "deceptive"? |
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3. Fallacy: a type of mistake in
argumentation that might appear to be correct, but which proves upon examination not to be
so. (This definition is clearly inadequate, but we will use it for a working definition.) |
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B. Let us classify two basic types: |
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1. Informal
Fallacy: those dependent upon language-- i.e., a fallacy that arises from the content
of an argument (the what is said, not the how it is said). |
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2. Formal
Fallacy: those outside the content of language--i.e., a fallacy that arises from an
error in the form of an argument; it is (usually) independent of content. |
| II. The following chart of fallacies, with some suggestive
examples, is an indication of some of the terrain to be discussed. |
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Fallacies |
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Informal |
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Formal |
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| Relevance |
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Presumption |
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Syllogistic |
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Symbolic |
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| ad baculum |
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Complex
Question |
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Exclusive
Premisses |
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Affirming the Consequent |
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| III. In our discussion of informal fallacies, we will also
look at arguments which initially seem to be fallacious because they are drawn along the
same lines, but are not not really so. |
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A. Once the fallacies are introduced, there is a
tendency to see a fallacies in passages where there are just appeals and
no arguments present. Unless an argument is present, no fallacy
can occur. |
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B. Thus, before the labeling of
"fallacy" is done with respect to a passage, one must be sure that an
argument is being given. (An argument must have at least two statements: a premiss and a
conclusion.) You will find many textbooks talk about appeals rather than
arguments--a topic related to "disagreements in belief and attitude" discussed in Logic and Language and similar
to "arguments and nonarguments" discussed in The Nature of Arguments.
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Philosophy
103: Introduction to Logic
