Lesson 32: Establishing Conclusions

Question 1

How do you establish a conclusion?

Answer 1

Take a given statement as a conclusion, then find a valid argument form that could be used to establish that conclusion.

Question 2

How many valid forms of syllogisms are there?

Answer 2

There are 24 valid forms of syllogisms—six moods for each of the four figures.

Question 3

The 24 valid forms of syllogisms:

Answer 3

AAA-1, AAI-1, AII-1, EAE-1, EAO-1, EIO-1, AEE-2, AEO-2, AOO-2, EIO-2, EAO-2, EAE-2, AAI-3, AII-3, EIO-3, OAO-3, IAI-3, AAI-4, AEE-4, AEO-4, EAO-4, EIO-4, EAO-4, EIO-4, IAI-4

Question 4

What is the procedure for proving a claim to be right?

Answer 4

1. Put the statement to be established into categorical form.
2. Find a valid argument form (mood and figure) which has that type of statement as the conclusion.
3. Place the statement as the conclusion of the selected form of syllogism, and fill in the known terms, leaving the middle term blank.
4. Find a middle term that makes the premises true, thus completing the argument.