Sample/ Guide: What is the name of fallacy: A implies B. Therefore C?

Question

The sample below is a guide for fallacy questions

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I want to know the name of a fallacy.

Here's the text:

Blah blah blah blah blah

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Note that the title includes a basic description of the fallacy -- and not just the question "what is this fallacy?"

Answer 1

The answer here addresses a common issue with fallacy questions

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One problem that many fallacy questions suffer from is a very strong desire to name the fallacy. This is not the most important thing with fallacies.

First off, it's important to understand that a fallacy in philosophy is an error in the reasoning of an argument. There are two basic kinds of fallacies: formal and informal fallacies.

Formal fallacies are easier to define and these fallacies capture errors in deductive reasoning. The two most well known are denying the antecedent and affirming the consequent. In these cases, the move is not valid where valid is a technical term relating to whether or not a deductive argument is truth-preserving. If you find one of these in an argument that purports to be deductive, naming the fallacy is useful as it points an error everyone will admit.

Informal fallacies are unfortunately a much messier business. Informal fallacies capture possible errors in arguments. And as such they present two problems. First, some fallacies have lots of names or lots of overlap with other fallacies. *There may not even be a name for a fallacy. Second, even if there is a name that might apply to the argument, it is sometimes debatable whether what is happening is fallacious.

Consider the following:

(1) Bob says that I've got cancer. Ergo, I have cancer.

As written this seems like an "appeal to authority" But whether this is fallacious depends on whether Bob is ...

(2) Bob is my smart friend

(2`) Bob is my local psychic

(2``) Bob is the leading oncologist in my country

But there may be reasons to see even 2`` as fallacious. Most of us would not find that to be an inappropriate, i.e. fallacious appeal, to authority, but it it is an appeal to authority.

A similarly tricky one is the "slippery slope" fallacy. A slippery slope looks formally similar to a valid deductive structure, hypothetical syllogism (A -> B, B -> C, thus. A -> C). It's fallacious when the implications between A, B, C, D, E, F, and G are dubious. But what's dubious for one might not be for another.

smoking causes carbon emissions. carbon emissions work as greenhouse gases in the atmosphere. Higher greenhouse gases in the atmosphere raise temperatures. Raised temperatures will sink the Maldives under water. If the Maldives sink under water, then hundreds of people will die. Ergo, you smoking causes hundreds of people to die.

This is clearly fallacious, but we could come up with an equally long chain that's valid if there were not dubious inferences in between.