I. We continue our discussion of the syllogistic fallacies with the third and fourth fallacies on our
list. Consider the following argument.
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All [subversives]D
are [radicals]U.
No [Republicans]D are [subversives]D.
No [Republicans]D are [radicals]D.
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A. We can see from the Venn Diagrams
corresponding to this argument that this argument is fallacious. |
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B. When we plug in the distribution statuses for
the classes in each argument from the chart learned
when we studied categorical propositions, we notice something interesting.
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C. Notice how in the argument, the major term
"P-radicals" is undistributed in the major premiss, but is distributed in
the conclusion.
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1. Since a term is said to be
"undistributed" when not every member of the class is being referred to, and a
term is said to be "distributed" when each and every member of the class is
being referred to, we are reasoning from information about part of a class to information
about the whole of the class. |
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2. When reasoning from a few instances to a
conclusion involving all instances, we are, metaphorically speaking, committing the
fallacy of converse accident. |
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That is, in the premiss, we are referring to
"some radicals" and then reasoning to "all radicals" in the
conclusion. |
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Another way of looking at this fallacy is to
compare the process with subalternation on the
Square of Opposition. |
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We are moving from a subaltern being true (some
radicals) to a superaltern being undetermined (all radicals) in truth value . |
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3. Since this fallacious reasoning involves the
major term in the syllogism, the fallacy committed there is termed the Illicit Process
of the Major Term or Illicit Major, for short.
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D. The Fallacy of the
Illicit Major occurs when the major term is undistributed in the premiss but is
distributed in the conclusion (but not vice versa!). |
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E. The second argument is as follows.
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All [good citizens]D
are [nationalists]U
All [good citizens]D are [progressives]U
All [progressives]D are
[nationalists]U
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1. We can see from the Venn Diagram for this
argument that it is fallacious.
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2. When we plug in the distribution statuses for
the classes in each argument from the chart learned
when we studied categorical propositions, we notice something interesting.
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F. Notice how in the argument, the minor term
"S-progressives" is undistributed in the minor premiss, but is distributed in
the conclusion.
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1. As in the first argument above, we are moving
from referring to some of the progressives in the premiss to referring to all of the
progressives in the conclusion |
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3. Since this fallacious reasoning involves the
minor term in the syllogism, the fallacy committed there is termed the Illicit Process
of the Minor Term or Illicit Minor, for short.
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G. The Fallacy of the
Illicit Minor occurs when the minor term is undistributed in the premiss but is
distributed in the conclusion (but not vice versa). |
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Rule: In a valid standard form categorical
syllogism no term can be distributed in the conclusion unless it is also distributed in
the premisses …
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Reason: ...otherwise the conclusion would
assert more than what is contained in the premisses. |
