answer to this discussion prompt and reply to these 2 comments –

  • What is the difference between a fallacy of relevance, a fallacy of weak induction, and a fallacy of ambiguity?
  • Provide at least one example of each, either something that you’ve heard or construct your own.

In addition to your main response, you must also post substantive responses to at least two of your classmates’ posts in this thread.

During World War II, first Japanese and then American forces built airbases in Melanesia – remote islands in the South Pacific. The Melanesians had no prior contact with the outside world – no electricity or mass-produced consumer goods. These huge armies arrive…build airstrips, radar towers and…whoosh…planes land full of food and clothes and radios. All the miracles of modern technology.

Then the war ended and the armies left. And the Melanesians, who had gotten used to all this new stuff, wanted it back. So, what did they do?

They built their own airstrips and radar towers out of reeds. They made airplanes out of bamboo. None of this stuff worked, of course, but it looked like what had been there before. Then they waited for new airplanes to come, loaded with more goodies.

The Melanesians fell victim to a very human way of thinking. They recognized one new event (the creation of the airstrip) and a second new event (the arrival of the supply planes) and they decided that the first event caused the second. On the one hand, that’s clever. But we all know the planes aren’t going to be landing in Melanesia anytime soon (well, they land there now to take people to fancy resorts, but that’s another story). The Melanesians fell victim to a fallacy – a mistake in reasoning where their premises didn’t logically support their conclusion. The particular fallacy on view here is post hoc ergo propter hoc which in English means “after that, therefore because of it” and it gets all of us.

And that’s the real trouble with fallacies. They’ve got a hotline right to our caveman brain and our cognitive biases, and they work. That’s why you’ll see so many fallacies in advertisements and political speech. Our job as critical thinkers is to have a good filter – to identify these fallacies so they can’t work on our decision making. Go hunt for some real life fallacies. Post the examples you find (if you share a youtube video you can use the mashup function to embed it right into your post) and identify and explain the fallacy using the terms from chapters 6 and 7. Once you start looking, you’ll be amazed how common these fallacies really are!

comment 1

A fallacy is a mistake in reasoning. This simply leads an argument unsound or invalid because the supporting details do not really support or prove the argument. Here are three types of fallacies that will be explained: a fallacy of relevance, a fallacy of weak induction, and a fallacy of ambiguity. First, fallacy of relevance, which is also called red herrings, is when a premise is not relevant to its argument. Speakers or writers commits a fallacy of relevance due to many reasons. One reason among them is when a speaker directs an argument at the person instead of at what the other person said. This is called Argumentum Ad Hominem (argument to the person) The following is an example: “My doctor said smoking cigarette can cause lung cancer. I do not think it is true because I saw him smoking the other day.” This person argues that the doctor’s claim is not true by discussing the doctor instead of insisting reasonable premises. Therefore, the premise is not properly relevant to the argument.

Second, fallacy of weak induction is when supporting details are too weak to raise the probability of its conclusions. It occurs when speakers insist a claim by generalizing too few supporting details. This is commonly called Hasty Generalization. For example, a lady insists, “all young boys hate carrots” after seeing a young boy not eating carrots at a restaurant. The lady’s claim is a fallacy because she generalized it from only one case to speak whole group of population. This generalization results the supporting detail weak and inadequate.

Last, fallacy of ambiguity is when an argument is uncertain because its supporting detail includes misused languages, forms, syntax etc. An example of ambiguity fallacy is Amphiboly, which misleading grammatical structures of sentence make the whole argument unclear. Look at the following example: “I like cooking my family and friends.” This example missed a word “for” between ‘cooking” and “my family” and changed the whole sentence scary. This false grammatical structure made the argument and conclusion ambiguous.

comment 2

A fallacy is a mistaken belief, a failure of reasoning or a faulty reasoning, which misleads arguments or base a invalid argument.

Fallacy of relevance is arguments that occur that have law that ae logically irrelevant to the conclusion, but also premises can appear to also be psychologically relevant. Therefore, conclusion can seem to follow from the premises. “The fallacies appeal to evidence or examples that are not relevant to the argument on hand.” Ex: Parents tell children that telling a lie is wrong, but they lie about Santa Claus.

Fallacy of weak induction happens not because of logically irrelevant conclusions but instead. Because the connection between premises and conclusion is not strong enough to support the conclusion. The premises show a little evidence in order to support the conclusion, however it is not good enough to have person believe the conclusion. When the premises is not strong enough in order to support the conclusion. Ex: A mom says that all kids hate vegetables, only because her kids hate vegetables

Fallacy of ambiguity come to light from the use of ambiguous language in the premises or conclusion, or even both. It is a fallacy in which the arguer misinterprets ambiguous statements, and produce a conclusion based on defective interpretation; come from something simple like a mistake in punctuation or grammar. It contains more than one meaning. For example, “ a good life depends on a liver.” This states that a healthy liver will help with living. Ex: A husband calls his wife to say that he can’t pick up the kids and she understood that he can pick up the kids.