Logical Fallacies

Logical Fallacies Or weak argument

What is a logical fallacy? • A logical fallacy is an error in logic that can make a plausible, but misleading argument. • Inductive fallacies: • Inductive fallacies are the result of the incorrect use of evidence. • Ex: “This chalk is white; therefore, all chalk is white.” • *With inductive fallacies, an arguer leaps to a conclusion based on insufficient evidence* • Deductive fallacies: • Deductive fallacies are the result of a failure to follow the logic of a series of statements. • Ex: “The rooster crows at 5:00 AM, and the sun rises at 5:00 AM; therefore the rooster makes the sun rise.” • *With inductive fallacies, an arguer makes an incorrect or unsupported link between cause and effect*

Logical fallacies continued… • While there are two main categories of logical fallacies, it is important to note that there is often overlap. • Some fallacies may fit into bothcategories. • It is also important to note that logical fallacies occur when : • An arguer incorrectly links cause and effect. • An arguer leaps to a conclusion based on insufficient evidence. • Most logical fallacies masquerade as reasonable statements, but they are in fact attempts to manipulate readers by reaching their emotions instead of their intellects.

Ad hominem • Directly attacks someone’s appearance, personal habits, or character rather than focusing on the merit of the issue at hand. • Latin for “against the man.” • EX: Ernest Hemingway was an alcoholic and a terrible father, so I won’t read his books. • EX: Michael Moore attacks Bush • http://www.youtube.com/watch?v=xZwrteFNic4

Appeal to authority • AKA Faulty Use of Authority. Someone tries to demonstrate the truth of a proposition by citing some person who agrees, even though that person may have no expertise in the given area • EX: AARP Medical Care commercial • http://www.youtube.com/watch?v=IRPHHAIAtks

Appeal to tradition • Argument that a policy, behavior or practice is right or acceptable because “its always been done that way” • EX: Life Cereal commercial • http://youtu.be/-4BEJ7BCZww

Begging the question • An argument that asks the reader to simply accept the conclusion without providing real evidence. • EX: Women should not be permitted into the men’s club because the club is only for men.

Circular Reasoning • This is a kind of circular argument where the support only restates the claim. • EX: Wrestling is dangerous because it is unsafe. • EX: Jogging is fun because it is enjoyable. • EX: Seinfeld • http://www.youtube.com/watch?v=OAVp6gnIgHY

Fallacy of ignorance • Assuming something is true simply because it hasn't been proven false • EX: Global warming is true because nobody has demonstrated conclusively it is not. • EX: People have been trying for years to prove that God does not exist. But no one has yet been able to prove it. Therefore, God exists.

False analogy • A false analogy claims comparison when differences outweigh similarities. • EX: If we can put a man on the moon, why can’t we find the cure for the common cold? • EX: Mercedes commercial • http://www.youtube.com/watch?v=S8LydU2P7Yw&list=PLvJVy54kigVt0TdazYzWPnP4rHUQHxLTm&feature=share&index=2

False dilemma • Poses an “either/or” situation by suggesting that only two options are possible. • *Sometimes called the “black/white” fallacy* • EX: If you don’t watch football, you’re not a real man. • EX: Either go to college or forget about making money. • EX: According to Jim • http://www.youtube.com/watch?v=Dln3DJEcghY

Hasty Generalization • Making a sweeping statement and expecting it to be true of every specific case; aka “stereotyping”. • EX: My roommate said her philosophy class was hard, and the one I'm in is hard, too. All philosophy classes must be hard. • EX: Taco Bell commercial • http://youtu.be/pem_FwggPsM (Only show first 26 seconds)

Post hoc ergo proctor hoc • Translates as "after this, therefore because of this." • Assuming that because B comes after A, A caused B. • EX: The rooster crows at 5:00 AM, and the sun rises at 5:00 AM; therefore the rooster makes the sun rise. • EX: Big Bang Theory video • http://youtu.be/vRJUvFG8gbE

Slippery slope • Claiming that one event will trigger a series of similar, undesirable events. • *If an arguer fails to provide evidence to support his or her claim that one event will lead to a similar, undesirable event, then they are guilty of the “slippery slope” fallacy. • EX: Cloning animals should be illegal because that would lead to cloning humans, and then we would have a race of clones. • EX: Direct TV Video • http://www.youtube.com/watch?v=VOvrJFZ8DtU

Straw man • The arguer makes his own position appear stronger by misrepresenting hisopponent’s position. (to knock down the other person as if he was made of straw) • EX: Listen, you trust-fund babies and children of privilege, if you’re going to drink a quart of bourbon every day and smoke crack, this book is not for you. • EX: Presidential campaign video • http://youtu.be/8s10r3ETpqE

Red herring • When the arguer changes the subject and take the listener down a different, unrelated path. Often, the arguer never returns to the original issue. • EX: The opposition claims that welfare dependency leads to higher crime rates - but how are poor people supposed to keep a roof over their heads without our help? • EX: Fish • http://www.youtube.com/watch?v=oBhK0_HjVe0 • EX: Presidential debate video • http://youtu.be/D6VmYOFGpbM

Ad Populum • AKA Bandwagon. The arguer appeals to the sheer number of persons who agree with the belief or to the popularity of the belief as evidence that it is true. EX: 4 out of 5 dentists recommend brushing with pure cane sugar. • EX: Billy Madison clip • http://youtu.be/1XICd91cwKo

Two wrongs make a right • A rebuttal to an argument which does not refute the allegations, but simply counterattacks. It assumes that if one wrong is committed, then another will cancel it out. • EX: My step dad says I’m irresponsible, but I’m not. Besides, he’s a jerk. • EX: Don't accuse me of cheating on that test, you always cheat on your tests.

Logical Fallacies