Categorical Syllogism Practice Name__________________________
“Fallacious and misleading arguments are most easily detected if set out in correct
syllogistic form.” – Immanuel Kant.
Exercises
Rewrite each of the following syllogisms in standard form, and name its mood
and figure. Procedure:
1) Identify the conclusion.
2) Note its predicate term, which is the major term of the syllogism.
3) Identify the major premises, which is the premise containing the major term.
4) Verify that the other premise is the minor premise by checking to see that it
contains the minor term, which is the subject term of the conclusion.
5) Rewrite the argument in standard form: major premise first, minor premise
second, conclusion last.
6) Name the mood and figure of the syllogism.
Example:
Some evergreens are objects of worship, because all fir trees are evergreens, and some
objects of worship are fir trees.
Step 1: The conclusion is: Some evergreens are objects of worship
Step 2: “objects of worship” is the predicate term of this conclusion, = major term
of the syllogism
Step 3: The major premise, the premise that contains this term, is “some objects of
worship are fir trees”
Step 4: The remaining premise, “all fir trees are evergreens” is the minor premise
since it contains the subject term of the conclusion: “evergreens”
Step 5: In standard form this syllogism is written thus:
Some objects of worship are fir trees.
All fir trees are evergreens.
Therefore, some evergreens are objects of worship.
Step 6: The three propositions in this syllogism are, in order, I, A, I. The middle
term, “fir trees”, is the predicate of the first premise, and the subject of the second, so the
syllogism is in the fourth figure. The mood and figure of the syllogism are: IAI-4--valid
1. Some conservatives are not advocates of high tariff rates, because all advocates of high
tariff rates are Republicans, and some Republicans are not conservatives.
Step 1: (conclusion)
Step 2: (major term or predicate of conclusion)
Step 3:major premise:
Step 4:minor premise & term (subject of conclusion)
Step 5:standard form: major premise, minor premise, conclusion:
Step 6: mood and figure (placement of the middle term)
2. No television stars are certified public accountants, but all certified public accountants
are people of good business sense; it follows that no television stars are people of good
business sense.
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
3. All CD players are expensive and delicate mechanisms, but no expensive and delicate
mechanisms are suitable toys for children; consequently, no CD players are suitable toys
for children.
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
4. No sports cars are vehicles intended to be driven at moderate speeds, but all
automobiles designed for family use are vehicles intended to be driven at moderate
speeds, from which it follows that no sports cars are automobiles designed for family use.
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
