Index of Logical Criticisms

Abuse of Principle

• Definition: Attempting to refute a principle (or the reasoning that it supports) by showing that it is has exceptions, but giving no reason to believe that the principle is generally unreliable or that the exceptions apply to the particular case at hand.
  MOI:  Identify the principle and the alleged exceptions in the absence of reasons for thinking the exceptions cast doubt on the reliability of the principle as stated.

Ad Hominem

• Definition:  Evaluating reasoning by calling attention to the character, actions or personal circumstances of the reasoner, rather than examining the reasoning itself.
  MOI:  Show how the the example focuses attention on the character, actions, or personal circumstances of the reasoner rather than examining the reasoning itself.

Argument from Ignorance

• Definition:  Attempting to refute (or support) a claim simply by appealing to ones ignorance of any evidence for (or against) it. 
• MOI: Show how the person attempts to establish a conclusion by appeal to his ignorance of evidence against it.  Then show why his ignorance is not a compelling basis for accepting his conclusion.

Contradiction

• Definition:  Being logically committed to the truth of some  statement S and it's denial not-S at the same time.
• MOI:  Identify the statement and reconstruct the reasoning by which they are logically committed to both its assertion and its denial.

Equivocation

• Definition: Using a word or expression in a sense that is alien to the given context without adequate notice or justification.
• MOI:  Identify the word or expression in question and identify the two different senses that have been equivocated upon:  (1) the sense that would normally be assumed in the given context and (2) the sense that is being assigned without adequate notice or justification.

Innuendo

• Definition:  Exploiting contextual assumptions to suggest a conclusion that has been neither stated nor logically implied, when there are reasons for doubting that one would be willing to claim it explicitly.
• MOI:  Identify the suggested conclusion, showing how, in the given context, it might be reasonably inferred despite the fact that it was neither stated nor implied.  Give reasons for doubting that it's author would claim it explicitly.

Red Herring

• Definition:  Distracting attention from an issue by confusing it with a different issue that is irrelevant or only superficially related to the one at hand.
• MOI:  Identify the issue at hand and identify the irrelevant issue being introduced.  Show why the new issue is irrelevant and why introducing the irrelevant issue has the effect of confusing the two issues, rather than simply explicitly refocusing attention on the new issue.

Straw Man

• Definition: Attempting to discredit a view (or practice) by criticizing a weak version of it or the reasoning given in support of it.
• MOI: Identify both the original view and the weak version of that view.  Show (a) why the weak version is a version of the view  and (b) why it  is weak.

Weak Comparison

• Definition: Basing a conclusion on an alleged similarity between two or more things when it is not clear that the similarity in question is (a) sufficiently strong or (b) sufficiently relevant to the context to provide adequate support for conclusion.
• MOI:  Explicitly identify the similarity in question and identify why you think it is insufficiently strong or insufficiently relevant to the context to warrant the conclusion.

Weak Distinction

• Definition Basing a conclusion on an alleged distinction between two or more things when it is not clear that the distinction in question is (a) sufficiently strong or (b) sufficiently relevant to the context to provide adequate support the conclusion.
• MOI:  Explicitly identify the distinction in question and identify why you think it is insufficiently strong or insufficiently relevant to the context to adequately support the conclusion.

Weak Reason

• Definition:  Using a reason the truth of which is not sufficiently likely to justify the degree of confidence with which it (or the conclusion it supports) has been expressed.
• MOI:  Identify the reason in question.  Show why you think the reason is unlikely to be true or at least not likely enough given the degree of confidence with which it has been expressed.

Weak Principle

• Definition:  Using a principle that is not sufficiently reliable to justify the expressed degree of confidence in the conclusion it supports.
• MOI:  Identify the principle in question and its apparent level of reliability.  Show why you think the author of the reasoning has too much confidence in the conclusion given the reliability of the principle.