1. 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

2. Fallacy
Definition: reasoning that is unsound

3. 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.

4. 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.

5. 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

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

7. 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

8. 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.

9. 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…

10. 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?)

11. 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.

12. 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.

13. 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?)

14. 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)