IQ Test Labs

touch_app

Distributivity

The terms in statements will be distributed according to the following rules, and apply to both the premises and the conclusion:

• The predicate, (P), is distributed in negative statements, such as 'No' and 'Some not'.
• The subject, (S), is distributed in universal statements, such as 'All' and 'No'.

Validity and the distribution of terms.

Premises:

All A is B

All B is C

Conclusions:

All A is C

Some C is A

Middle term:

If the middle term is not distributed in at least one of the two premises, then the argument is not valid. (Fallacy of the undistributed middle).

• The middle term is the common term between two given premises.
• A distributed term has a check mark above it.

In this case, B is the middle term and it is distributed in the second premise.

Terms in conclusion.:

When the major term is distributed in the conclusion, it should also be distributed in the major premise (fallacy of the illicit major), and when the minor term is distributed in the conclusion, it should also be distributed in the minor premise (fallacy of the illicit minor).

As a general rule, if a term is distributed in the conclusion, the term must be distributed in at least one of the premises.

Conclusion 1: 'A' is distributed and it is also distributed in the first premise; the argument is valid.

Conclusion 2: No term has a checkmark; the argument is valid.

Example 2::

Premises:

All A is B

No B is C

Conclusions:

No A is C

Some A is not C

Middle term:The middle term is distributed in the second premise.

Conclusion 1: Both terms have checkmarks in both the conclusion and the premises; conclusion 1 is valid.

Conclusion 2: 'C' is distributed in the second premise; conclusion 2 is valid.