Introduction to Logic: Reading Exercises

Introduction to Logic: Reading Exercises
6.1 INSTRUCTIONS
Rewrite each of the following syllogisms in standard form, and name its mood and figure. (Procedure: first, identify the conclusion; second, note its predicate term, which is the major term of the syllogism; third, identify the major premise, which is the premise containing the major term; fourth, 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; fifth, rewrite the argument in standard form—major premise first, minor premise second, conclusion last; sixth, name the mood and figure of the syllogism.)
Example Problem
No nuclear-powered submarines are commercial vessels, so no warships are commercial vessels, because all nuclear-powered submarines are warships.
Example Solution
Step 1.

The conclusion is “No warships are commercial vessels.”

Step 2.

“Commercial vessels” is the predicate term of this conclusion and is therefore the major term of the syllogism.

Step 3.

The major premise, the premise that contains this term, is “No nuclear-powered submarines are commercial vessels.”

Step 4.

The remaining premise, “All nuclear-powered submarines are warships,” is indeed the minor premise, because it does contain the subject term of the conclusion, “warships.”

Step 5.

In standard form this syllogism is written thus:


No nuclear-powered submarines are commercial vessels.All nuclear-powered submarines are warships.Therefore no warships are commercial vessels.

Step 6.

The three propositions in this syllogism are, in order, E, A, and E. The middle term, “nuclear-powered submarines,” is the subject term of both premises, so the syllogism is in the third figure. The mood and figure of the syllogism therefore are EAE-3.

PROBLEMS
2. Some evergreens are objects of worship, because all fir trees are evergreens, and some objects of worship are for trees.
Step 1: The conclusion is “All fir trees are evergreen”
Step 2: “Objects of worship” is the predicate term thus, the major syllogism.
Step 3: “some objects of worship are evergreen” is the major premise
Step 4: “Therefore, some evergreens are objects of worship” is the minor premise
Step 5: “All fir trees are evergreens, some evergreens are objects of worship, and some objects of worship are evergreens” is the standard syllogism.
Step 6: IAI-4
3. All artificial satellites are important scientific achievements; therefore some important scientific achievements are not U.S. inventions, in as much as some artificial satellites are not U.S. inventions.
Step 1: Some important scientific achievements are not U.S. inventions is the conclusion thus the predicament term of the conclusion is “ scientific achievement”
Step 2:The major term that contain the major premise is “ some scientific achievement are not U.S. inventions”
Step 3: the minor premise is that “some artificial satellites are not U.S. inventions&r...