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Philosophy 103: Introduction to Logic
Test on Categorical Syllogisms

To access questions with a java enabled browser,  click here:  CATEGORICAL SYLLOGISMS TEST

I. Logical Analogies (15 points). Attempt to refute the two arguments below by the method of devising a logical analogy. If the argument cannot be refuted, state why.

1. All persons who worry are people who live in the future.

All persons who plan ahead are people who live in the future.    
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All persons who plan ahead are persons who worry.

This argument is just like arguing

All cats are animals.
All dogs are animals.
All dogs are cats.

The Fallacy of the 
Undistributed Middle Term.

2. Some procrastinators are lazy persons.

No self-actualized persons are lazy persons.
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Some self-actualized persons are not procrastinators.

This argument is just like arguing

Some animals are cats.
No dogs are cats.
Some dogs are not animals.

Fallacy of the Illicit Process of the Major Term

II. Standard Form Syllogisms (55 points). Test the following arguments for validity by Venn Diagrams and Syllogistic Fallacies.

1. No loving persons are thoughtless persons.

No loving persons are aggressive people.
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No aggressive people are thoughtless persons.

Fallacy of Exclusive Premisses

2. No passive individuals are folks who live well.

All self-actualized persons are folks who live well.
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No self-actualized persons are passive individuals.

Valid.  No Fallacy Committed.

3. All persons living the life of excellence are open people.

All open people are honest folks.
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All honest folks are persons living the life of excellence

Fallacy of the Illicit Process of the Minor Term.

4. Some studious persons are not friendly persons.

All friendly persons are persons who value others.
--------------------------------------------------
Some persons who value others are not studious persons

Fallacy of the Illicit Process of the Major Term.

5. All folks who live well are persons living the good life.

No persons living the good life are passive individuals.
--------------------------------------------------------
No passive individuals are folks who live well.

Valid.  No Fallacy Committed.

6. All individuals who cherish living are well adjusted people.

All perfect persons are individuals who cherish living.
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Some perfect persons are well adjusted people.

The Existential Fallacy

7. Some worriers are folks who live well.

Some passive individuals are not worriers.
------------------------------------------
Some passive individuals are folks who live well.

Invalid.  Fallacy of Affirmative Conclusion From A Negative Premiss.

8. All people cherishing living are persons living excellent lives.

All folks who live well are people cherishing living.
---------------------------------------------------------
All folks who live well are persons living excellent lives.

Valid.  No Fallacy Committed.

9. All responsive individuals are considerate persons.

All persons who act before they think are responsive individuals.
-----------------------------------------------------------------
All persons who act before they think are considerate persons.

Valid.  No Fallacy Committed

10. All persons who seek fulfillment are persons who take risks.

No shy persons are persons who seek fulfillment.
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No shy persons are person who take risks.

Invalid.  Fallacy of the Illicit Process of the Major Term.

11. All persons living excellent lives are persons cherishing living.

All folks who live well are persons who cherishing living.
------------------------------------------------------------------
All folks who live well are persons living excellent lives.

Invalid.  Fallacy of the Undistributed Middle Term.

III. Syllogistic Arguments (30 points). Put the following arguments into standard form and order categorical syllogisms. Name the mood and figure, and test for validity by Venn Diagrams and the Syllogistic Fallacies.

1. No persons who plan ahead are persons who live in the present, since all persons who live in the present are satisfied people, and no persons who plan ahead are satisfied people.

All persons who live in the present are satisfied people.
No persons who plan ahead are satisfied people.
No persons who plan ahead are persons who live in the present.

Valid.

MOOD and FIGURE:  AEE-2

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2. No thing is better than being successful, but all doing poorly is better that no thing, so all doing poorly is better than being successful.

Four Term Fallacy.  "No thing" is being used in different senses.

MOOD and FIGURE:  None.

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3. No self-actualized persons are lazy people, and some self-actualized persons are happy people, hence some lazy people are not happy people.

Some self-actualized persons are happy people.
No self-actualized persons are lazy people.
Some lazy people are not happy people.

Illicit Process of the Major Term.

MOOD and FIGURE:  IEO-3

IV. Sorities (Optional 10 points). Can you state a sequence of interlocking valid arguments from Parts I-III of this test? If so, restate that argument below.

The conclusion of #8 is the same as the major premiss of #5.
The conclusion of #5 is the same as the major premiss of #2.

The sorities would be ...

All people who cherish living are persons who live the life of excellence.
All folks who live well are people who cherish living.
All folks who live well are persons who live the life of excellence.
No persons who live the life of excellence are passive individuals.
No passive individuals are folks who live well.
All self-actualized persons are folks who live well.
No self-actualized persons are passive individuals.

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