Logic

A lot of the problems with convincing people on Facebook or out in the real world is due to false or faulty logic also called Fallacies.

Fallacies

A fallacy is a particular type of error in deductive and inductive arguments. We may expand the term to include categories of errors in reasoning or persuasive techniques (rhetoric) that lead to untrustworthy, unsound, and improbable conclusions.

A Formal Fallacy is where facts are sequenced incorrectly or missing or false facts are inserted to take the place of the truth. It is an error of logic: the conclusion is not supported by the premises. Either the premises are untrue or the argument is invalid for lack of logical form. The form of the argument is wrong or missing a truthful premise, rendering the argument as nonsense.

Informal Fallacy

An Informal Fallacy denotes an error in what you are saying, that is, the content of your argument is in error. The ideas might be arranged correctly, but something you said isn’t quite right. The content of the argument is wrong or it is out of place.

Following is a list of informal fallacies that are most commonly encountered in discussion and debate.

• Ad Hominem
• Strawman Argument
• Appeal to Ignorance
• False Dilemma
• Slippery Slope Fallacy
• Circular Argument
• Hasty Generalization
• Red Herring Fallacy
• Tu Quoque
• Causal Fallacy
• Fallacy of Sunk Costs
• Appeal to Authority
• Equivocation
• Appeal to Pity
• Bandwagon Fallacy

Formal Fallacy

Aristotelian fallacies

• Fallacy of four terms (Quaternio terminorum);
• Fallacy of the undistributed middle;
• Fallacy of illicit process of the major or the minor term;
• Affirmative conclusion from a negative premise.

Affirming the consequent or fallacy of the converse or confusion of necessity and sufficiency,

Affirming a disjunct

Affirming a disjunct is a form of argument in which one disjunct of a disjunctive premiss is affirmed as a premiss, while the other disjunct is denied as a conclusion.

1. Max is a mammal or Max is a cat.
2. Max is a mammal.
3. Therefore, Max is not a cat.

Fallacy of the undistributed middle

This is a form of non sequitur which is a conclusion or statement that does not logically follow from the previous argument or statement.

Denying the antecedent

1. If A is true, then B is true.
2. A is false.
3. Therefore, B is false.