Basic Errors in Logic Featured in “Love is a Fallacy” By Max Shulman Fallacies Basic Errors in Logic Featured in “Love is a Fallacy” By Max Shulman

Fallacy Definition: reasoning that is unsound

Syllogism Formal logic is based upon the premises implying a necessary conclusion: Premise 1: All birds have wing. Premise 2: A cardinal is a bird. Conclusion: Therefore, a cardinal has wings.

Valid vs Sound A valid argument has a conclusion that is based on the logic of the premises. Premise 1: All men are logical. Premise 2: Socrates is a man. Conclusion: Socrates is logical. If one are both premises are false, then the argument is not sound.

Formal vs Informal Reasoning Deductive Reason – “whole to parts” starts with premises that lead down. It’s valid or invalid / Certainty Informal Inductive Reason – “part to whole” – begin with particular facts that lead to a general point It’s strong or weak/ Probability

Logical Fallacies Informal reasoning that is weak due to violating principles such as relevance, presumption, and clarity.

Examples of Fallacies Ad miseracordium (Appeal to Pity): uses sympathy instead of reason I really deserve a raise. If I don’t make more money I may lose my home. I hope you find the defendant “not guilty.” Show some sympathy! The poor guy is in a wheelchair

Examples of Fallacies Hasty Generalization: a conclusion is drawn about a population without enough instances for support Sam is riding her bike in her home town in Maine, minding her own business. A station wagon comes up behind her and the driver starts beeping his horn and then tries to force her off the road. As he goes by, the driver yells, ”Get on the sidewalk where you belong!" Sam sees that the car has Ohio plates and concludes that all Ohio drivers are jerks.

Examples of Fallacies Hypothesis Contrary to Fact: the hypothesis that begins the argument is untrue – no evidence to support it If I had not called you and reminded you about the test, you surely would have failed it. Someone else could have called, you might have remembered on your own, you might have looked in your agenda, etc…

Examples of Fallacies False Analogy: compares two unlike things Children are like dogs. They need to have strong discipline. (Should they also go to the vet and eat from a bowl on the floor?)

Examples of Fallacies Poisoning the Well: insulting/bad-mouthing your opponent My opponent is a complete liar. You can never believe what he says. You can’t be friends with her. She is a cheater.

Examples of Fallacies Post Hoc (Faulty Cause & Effect): an incorrect cause is identified We never had any problems with the plumbing until you moved into the building. Therefore, you must have caused the problems.

Examples of Fallacies Contradictory Premises: circular logic – one premise denies the other Into what shape of hole would a round square fit? (round square?) If God can do anything, can He make a stone so heavy He won’t be able to lift it? (can do anything but won’t be able?)

Examples of Fallacies Dicto Simplicitor (Unqualified Generalization): taking one example and applying it to everyone/everything That spotted horse is male. Therefore all spotted horses must be male. (all?) The things you learn in school don’t have anything to do with life. (find any way in which students learn a skill to use later in life and the statement is proven faulty)