A fallacy is a kind of error in reasoning. Logical fallacies are flawed, deceptive, or false arguments that can be proven wrong with reasoning. There are two main types of fallacies: A formal fallacy is an argument with a premise and conclusion that doesn't hold up to scrutiny. An informal fallacy is an error in the form, content, or context of the argument Key PointsTypes of logical fallacies: Appeal to unqualified Authority: Appeal to authority is the misuse of an authority's opinion to support an argument. While an authority's opinion can represent evidence and data, it becomes a fallacy if their expertise or authority is overstated, illegitimate, or irrelevant to the topic. "The great cricketer Sudhir says that Medisulpha soaps are good for health. We, therefore, must believe that it must be true indeed." this is an example of the appeal to an unqualified Authority fallacy. Additional Information