How To Debate On The Internet - Common Types of Logical Fallacies

I have picked some common errors in reasoning which tend to perpetuate around the internet forums, discussions and debates. These are basic fundamentals of logical discourse.
Having ability to logically shape and express our reasoning has many useful benefits including sharpness of thought, confidence and objectivity. This ability can also help us to decide when we should withdraw from the conversation, when it starts to appear as pointless.

Ad Hominem - Abusive Type

It means personally attacking the character of the person that brings the argument, instead of debating the argument alone.

Premise 1 : A is claiming X.
Premise 2: There is something objectionable about A ("A is and idiot").
Conclusion: Therefore X must be false.



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Slippery Slope (Domino Fallacy)

It is an is a common logical fallacy that suggests that some less important event can produce more important significant event, which then will produce even more important event until some definitive event is reached.
This fallacy presumes that all the following events are inevitable, while providing no evidence to support this clam. This argument tends to exploit people's fears.

Premise 1 : If A, then B,
Premise 2: If B, then C...
Conclusion: ... Then ultimately D.



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Circular Reasoning (Begging The Question, Paradoxical Thinking)

A type of reasoning in which a person presumably or definitively assumes the conclusion in one or more of the premises, creating a circle in reasoning.

"You're obviously wrong, because you are making no sense"

Person A: God exists.
Person B: Why should I believe that claim?
Person A: Because the Bible says so.
Person B: Why should I believe the Bible?
Person A: Because the Bible is a word of God.



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Genetic Fallacy

A type of logical fallacy when an argument defended or rejected merely, because the origin of its claim or premise.
For example, claiming that an idea, person or object must be credible (or not credible), just because of its race, ethnicity or geographic background.
This logical fallacy is related to ad hominem fallacy.

Premise 1: Person A said X is true.
Premise 2: Person A is a bad source.
Conclusion: Therefore X must be false.



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Argument From Authority (The Appeal To Irrelevant Authority)

Referring to authority as evidence, when the authority is not really an authority who is an expert on the issue.
Irrelevant authority could be a famous person or a source.
This type of logical reasoning tried to exploit the feeling of respect or familiarity with certain popular person or source.
Of course, it is reasonable to appeal to relevant authority like experts in the field.

Premise 1: Experienced people are usually correct.
Premise 2: Those people say X is correct.
Conclusion : Therefore X is definitely correct.



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Red Herring (Changing The Subject, Beside The Point)

It is a deliberate attempt to take an attention from an argument to different issue, with an attempt of discarding the argument.
It is logically fallacious reasoning, because changing the subject of debate does not count as an argument against a claim.

Subject A is being discussed.
Subject B is being introduced which has no relevance to topic A.
Subject A ends up being abandoned.



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Straw Man

An attempt to win the argument by creating a misrepresented, twisted or overblown version of the argument and then attacking that substituted version.
It happens when a person deliberately misrepresents an opponent's argument to make the opponent's argument look like it can be easily rejected.

Person A raises argument X1.
Person B describes argument X1 as argument X2 (Straw Man Argument).
Person B refutes argument X2.
Person B claims that argument X1 has been refuted.



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Appeal To Ignorance (Appeal To A Lack Of Evidence, Negative Proof )

Claiming that some premise must be factual just because there is not enough of evidence proving that it is not, or that a premise must be untruthful, because it has not been proven factual.

"God must exist, because no one has been able to prove that it does not exist"



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Association Fallacy (Guilt By Association)

This logical fallacy occurs when an a person or idea is discredited, because of it's association with some upopular or undesirable group, person or belief.

Premise 1: Person A is a member of group B.
Premise 2: Person A is a member of group C
Conclusion: Therefore B is C



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No True Scotsman

A person can make a universal claim about category of things.
When a claim is confronted with evidence which challenges it, rather than accepting or rejecting the evidence, a person counters the challenge by modifying the criteria of membership into that category, without giving reference to any specific objective rule.

Premise 1: All A are B.
Premise 2: Evidently, not all A are B.
Conclusion: All true A are B.



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I hope that you enjoyed reading my post.
-logic

[For writing this article I used help of different sites such as Logically Fallacious and Rational Wiki ]