Fallacies
A fallacy is a mistake in reasoning.
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Fallacies are often initially persuasive.
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Fallacies are sometimes categorised as being either 'formal' or 'informal'.
Why do Fallacies Arise?
A premise of the argument is false.
A premise of the argument is true but is irrelevant to the conclusion.
The premise is the conclusion.
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A deductive argument has an invalid structure.
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An inductive argument makes a weak inductive inference..
How to Evaluate Arguments and Identify Fallacies
First, identify the conclusion and the premise. Then ask:
How are the premises related to the conclusion? Is there anything missing?
Do the premises provide good support for the conclusion, or is there some kind of error (either formal or informal) in the reasoning?
What Causes Fallacies?
Intention: Sometimes fallacies are intentionally used to persuad people of something.
Human Psychology: People sometimes have biases, presuppositions, and/or emotional construct or accept fallacious arguments.
Carelessness: Sometimes people make or accept reasoning errors simply because they are not being careful and paying attention.
What can we do to avoid fallacies?
Learn what fallacies there are.
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Pay attention and actively think about the reasoning involved in an argument.
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Identify and question presuppositions and background beliefs/worldwide views. (this is particularly hard when it comes to our own beliefs, but it is important to do if you want to present arguments that are reasonable and persuasive to other people)
Are All Fallacies Invalid?
Formal fallacies have an invalid form so will all be invalid:
e.g. Denying the antecedent
"If you are Scottish you must be British and since you aren't Scottish you can't be British".
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Informal Fallacies however can be perfect valid.
e.g. False Dilemma.
"Either you support Celtic or you support Rangers and since you don't support Celtic you must support Rangers."
This is valid but unsound as the first premise is false.
Information
Tasks
As part of higher Philosophy you are required to know several different types of fallacies.
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Download below to learn the different types, definitions and examples.