by James W. Benham and Thomas J. Marlowe
The first author came up with the original idea, based on William Safire's
collection of grammatical rules in a similar format. The second author
contributed many (perhaps most) of the examples. Responsiblity for
choosing the best ones rests exclusively with the first author.
- Ad hominem arguments are the tools of scoundrels and blackguards.
Therefore, they are invalid.
- If you had any consideration for my feelings, you wouldn't argue from an
appeal to pity.
- What would your mother say if you argued from an appeal to sentiment?
- I don't understand how anyone could argue from an appeal to incredulity.
- If you argue from an appeal to force, I'll have to beat you up.
- You are far too intelligent to accept an argument based on an appeal to
- Everyone knows that an argument from appeal to popular opinion is invalid.
- Circular reasoning means assuming what you're trying to prove. This form of
argument is invalid becuase it's circular.
- As Aristotle said, arguments from an appeal to authority are invalid.
- Post hoc ergo proptor hoc arguments often precede false conclusions.
Hence, this type of argument is invalid.
- Using the Argumentum ad Consequentiam makes for unpleasant discussions.
Hence, it must be a logical fallacy.
- The argumentum ad nauseum is invalid. The argumentum ad nauseum is
invalid. The argumentum ad nauseum is invalid. If three repetitions
of this principle haven't convinced you, I'll just have to say it again: the
argumentun ad nauseum is invalid.
- Ancient wisdom teaches that the argumentum ad antiquitatem is invalid.
- An argument is emotional and no substitute for reasoned discussion.
But proof by equivocation is a kind of argument. Thus, a proof by equivocation
is no substitute for a valid proof.
- If we accept slippery slope arguments, we may have to accept other forms
of weak arguments. Eventually, we won't be able to reason at all. Hence, we
must reject slippery slope arguments as invalid.
- A real logician would never make an argument based on the "No true
Scotsman" fallacy. If anyone who claims to be logical and makes arguments
based on this fallacy, you may rest assured that s/he is not a real logician.
- An argument based on a logical fallacy often leads to a false conclusion.
Affirming the consequent often leads to a false conclusion. Therefore, affirming
the consequent is a fallacy.
The following additional fallacies were sent in by Rev. Hugh Ryunyo King:
- The fallacy of the undistributed middle is often used by politicians, and
they often try to mislead people, so undistributed middles are obviously
- Reasoning by analogy is like giving a starving man a cookbook.
- Non sequitur is a Latin term, so that's a fallacy too.
- And I bet the gambler's fallacy is also invalid - I seem to be on a roll!
Please feel free to submit other logical fallacies (in never-say-never form) to
I will try to incorporate the best ones into this page, even at the expense of
replacing some of the ones above.
Last modified: December 18, 2002