###
Rule of Contradiction

Contradictory statements are statements that differ in both quality and quantity

###
Rule of Contraries

Two statements are contrary to one another if they are both universals but differ in quality

###
Rule of Subcontraries

Two statements are subcontrary if they are both particular statements that differ in quality

###
Rule of Subalterns

Two statements are subalternate if they have the same quality but differ in quantity

###
1st Rule of Opposition

Contradictories cannot at the same time be true nor at the same time be false

###
2nd Rule of Opposition

Contraries cannot at the same time both be true, but can at the same time both be false

###
3rd Rule of Oppostion

Subcontraries may at the same time both be true, but cannot at the same time both be false

###
4th Rule of Opposition

Subalterns may both be true or both be false

###
Rule of Double Negation

A term which is not negated is equivalent to a term that is negated twice

###
Essential Law of Argumentation

If the antecedent is true, the consequent must also be true

###
Principle of Reciprocal Identity

Two terms that are identical with a third term are identical to each other

###
Principle of Reciprocal Non-Identity

Two terms, one of which is identical with a third term and the other of which is nonidentical with that third term, are nonidentical to each other

###
Dictum de Omni

What is affirmative universally of a certain term is affirmed of every term that comes under that term

###
Dictum de Nullo

What is denied universally of a certain term is denied of every term that comes under that term

###
Rule I

There must be three and only three terms

###
Rule II

The middle term must not occur in the conclusion

###
Rule III

If a term is distributed in the conclusion, then it must be distributed in the premises

###
Rule IV

The middle term must be distributed at least once

###
Rule V

No conclusion can follow from two negative premises

###
Rule VI

If the two premises are affirmative, the conclusion must also be affirmative

###
Rule VII

If either premise is negative, the conclusion must be negative

###
Fallacy of Four Terms

There are four clearly distinguishable terms in a syllogism

###
Fallacy of Equivocation

One of three terms is used in argument in two different senses

###
Fallacy of Illicit Major

The major term is distributed in the conclusion but not in the major premise

###
Fallacy of Illicit Minor

The minor term is distributed in the conclusion but not in the minor premise

###
Fallacy of Undistributed Middle

The middle term is not distributed in either premise

###
Fallacy of Exclusive Premises

When rule V is violated

###
Fallacy of Drawing a Negative Conclusion from Affirmative Premises

when rule VI is violated

###
Fallacy of Drawing an Affirmative Conclusion from Negative Premises

when rule VII is violated

### Please allow access to your computer’s microphone to use Voice Recording.

## We can’t access your microphone!

### Click the icon above to update your browser permissions above and try again

Example:

### Reload the page to try again!

Reload

## Press Cmd-0 to reset your zoom

## Press Ctrl-0 to reset your zoom

### It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

## Your microphone is muted

### For help fixing this issue, see this FAQ.