# Notes

Topics: Syllogistic fallacy, Syllogism, Fallacy of the undistributed middle Pages: 2 (407 words) Published: February 5, 2013
Rules of Categorical Syllogism
Rule #1
FALLACY OF EQUIVOCATION - The middle must always be taken in the same sense. Ex. Father, party, speaker, mouse, bar
Rule #2
FALLACY OF ILLICIT PROCESS
* Illicit Major – The predicate is universal in the conclusion not in the major premise. * Illicit Minor – The subject is universal in the conclusion but not in the minor premise. Rule #3
FALLACY OF MISPLACED MIDDLE TERM – The middle term should not occur in the conclusion. A steward is a flight attendant; M + p But, a steward is a male;M + s

Therefore, a steward is a male flight attendant. M + sp

You are happy;M + p
But, you are energetic;M + s
Therefore, you are happy and energetic.M + ps
Rule #4
FALLACY OF UNDISTRIBUTED MIDDLE TERM – The middle term must be distributed universally, at least once, in the premises. All stewardesses are female;P + m
But, all mothers are female;S + m
Therefore, all mothers are stewardesses.S + p

All apples are fruits;P + m
But, some fruits are mangoes;m + s
Therefore, some mangoes are apples.s + p
Rule #5
FALLACY OF A NEGATIVE CONCLUSION DRAWN FROM AFFIRMATIVE PREMISES – Two affirmative premises cannot give a negative conclusion. All stones are hard;M + p
But, some diamonds are stones;s + m
Therefore, some diamonds are not stones.s – p ?
Rule #6
FALLACY OF NEGATIVE PREMISES - From two negative premises, nothing follows. A chair is not a table;P - M
But, a table is not a pen;M - S
Therefore, a pen is not a chair.S - P ?

No tenor is a soprano;P - M
But, no soprano is a baritone;M - S
Therefore, no baritone is a tenor.S – P ?
Rule #7
From two particular premises, nothing follows.
a. If both particular premises are affirmative, then the subjects and predicates are particular. Some men are gays;p + m
But, some gays are artists;m + s
Therefore, some...