Analyzing Arguments With Logic: Learn It 3

Types of Logical Fallacies

In the previous Learn-It, we saw that logical arguments can be invalid when the conclusion is not true, when the premises are insufficient to guarantee the conclusion, or when there are invalid chains in logic. There are a number of other ways in which arguments can be invalid, a sampling of which are given here.

The ideas sampled on this page are classic and are often found in irresponsible advertising, politics, and in social media. A good way to understand them is to see as many examples of them in the world as you can. Look at social media arguments that appeal to emotion and sentiment. Political candidates, too, sometimes employ one or more of these to favorably manipulate situations.

types of logical fallacies

  1. Ad hominem: An ad hominem argument attacks the person making the argument, ignoring the argument itself.
  2. Appeal to ignorance: This type of argument assumes something it true because it hasn’t been proven false.
  3. Appeal to authority: These arguments attempt to use the authority of a person to prove a claim. While often authority can provide strength to an argument, problems can occur when the person’s opinion is not shared by other experts, or when the authority is irrelevant to the claim.
  4. Appeal to consequence: An appeal to consequence concludes that a premise is true or false based on whether the consequences are desirable or not.
  5. False dilemma: A false dilemma argument falsely frames an argument as an “either or” choice, without allowing for additional options.
  6. Circular reasoning: Circular reasoning is an argument that relies on the conclusion being true for the premise to be true.
  7. Straw man: A straw man argument involves misrepresenting the argument in a less favorable way to make it easier to attack.
  8. Post hoc (post hoc ergo propter hoc): A post hoc argument claims that because two things happened sequentially, then the first must have caused the second.
  9. Correlation implies causation: Similar to post hoc, but without the requirement of sequence, this fallacy assumes that just because two things are related one must have caused the other. Often there is a third variable not considered.