4.1 What is a Fallacy?

A fallacy as a type of argument that may seem to be correct, but that proves, on examination, not to be so.

An argument whose premisses do not support its conclusion is one whose conclusion could be false even if all its premisses were true. In cases of this kind, the reasoning is bad, and the argument is said to be fallacious. A fallacy is an error in reasoning.

Each fallacy is a type of incorrect argument.

Examples:

4.2 Fallacies of Relevance

When an argument relies on premisses that are not relevant to its conclusion, and that therefore cannot possibly establish its truth, the fallacy committed is one of relevance.

R1. The Argument from Ignorance: Argument Ad Ignorantiam

The mistake is committed when it is argued that a proposition is true simply on the basis that it has not been proved false, or that it is false because it has not been proved true.

e.g. Criticism of Galileo

R2. The Appeal to Inappropriate Authority: Argument Ad Verecundiam

The fallacy ad verecundiam arises when the appeal is made to parties having no legitimate claim to authority in the matter at hand.

e.g. Asking Picasso to explain why our economic goes down.

R3.Argument Ad Hominem

A fallacious attack in which the thrust is directed, not at a conclusion, but at the person who asserts or defends it.

1. Abusive
2. Circumstantial

R4. The Appeal to Emotion: Argument Ad Populum

It replaces the laborious task of presenting evidence and rational argument with expressive language and other devices calculated to excite enthusiasm, excitement, anger, or hate.

R5. The Appeal to Pity: Argument Ad Misericordiam

A special case of the appeal to emotion, in which the altruism and mercy of the audience are the special emotions appealed to.

R6. The Appeal to Force: Argument Ad Baculum

The appeal to force, to cause the acceptance of some conclusion, seems at firs sight to be so obvious a fallacy as to need no discussion at all.

R7. Irrelevant Conclusion: Ignoratio Elenchi

The fallacy is committed when an argument purporting to establish a particular conclusion is instead directed to proving a different conclusion.

3. Fallacies of Presumption

P1. Complex Question

Asking a question in such a way as to presuppose the truth of some conclusion buried in that question.

P2. False Cause

P3. Begging the Question: Petitio Principii

To beg the question is to assume the truth of what one seeks to prove, in the effort to prove it.

P4 and P5. Accident and Converse Accident

4. Fallacies of Ambiguity

A1. Equivovation

A2. Amphiboly

A3. Accent

A4. Composition

A5. Division