Logical Fallacies What to Avoid in Your Argument

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Logical Fallacies What to Avoid in Your Argument

Logical Fallacies What to Avoid in Your Argument

Informational Slide on Fallacies � Murky reasoning that. . . � clouds an argument.

Informational Slide on Fallacies � Murky reasoning that. . . � clouds an argument. � leads to unsound conclusions. � Prevalent in the media and politics. � Most common: � Post Hoc, Ergo Propter Hoc (False Cause) � Hasty Generalization � Bandwagon � Affirming the Consequent � Ad Hominem � Slippery Slope

Post Hoc, Ergo Propter Hoc � “After This, Therefore Because of This” � Just

Post Hoc, Ergo Propter Hoc � “After This, Therefore Because of This” � Just because one event happened before another event, doesn’t mean the first event caused the second. � When the New York police department changed its policing tactics in the early 1990 s, the crime rate plummeted. But did the new police tactics cause the decline in crime? http: //www. youtube. com/watch? v=e. Vg. T-v. ZLK 6 Q

Hasty Generalization � Refers to claims based on insufficient or unrepresentative data. � The

Hasty Generalization � Refers to claims based on insufficient or unrepresentative data. � The news frequently carries stories about vicious pit bulls. Therefore, all pit bulls must be vicious. http: //www. youtube. com/watch? feature=player_embed ded&v=v 9 n. CPbbngm. I

Bandwagon � The popular ideas are necessarily right. � “Come on, everybody’s doing it”

Bandwagon � The popular ideas are necessarily right. � “Come on, everybody’s doing it” http: //www. youtube. com/watch? v=c. KMn-_a. Qo. Pk

False Analogy � Arguers often use analogies to support a claim. � While there

False Analogy � Arguers often use analogies to support a claim. � While there are similarities, there are usually differences as well. � Gun control will work in the United States because it works in England. It’s a mistake to force little Johnnie to take piano lessons because you can’t turn a reluctant child into a musician any more than you can turn a tulip into a rose. http: //www. youtube. com/watch? v=tzb. Z 14 KHAo. I

Either/Or Reasoning �A complex, multisided issue is reduced to two positions without acknowledging the

Either/Or Reasoning �A complex, multisided issue is reduced to two positions without acknowledging the possibility of other alternatives. � Either you are pro-choice on abortion or you are against the advancement of women in our culture. http: //www. youtube. com/watch? v=vt. P-S 9 OS 0 o 0

Affirming the Consequent � Premise: You loved The Matrix. � Premise: Keanu Reeves was

Affirming the Consequent � Premise: You loved The Matrix. � Premise: Keanu Reeves was in Speed. � Conclusion: You must love Speed. http: //www. youtube. com/watch? feature=player_embed ded&v=zrz. Mh. U_4 m-g

Ad Hominem � Attacking the person who is making the argument, rather than the

Ad Hominem � Attacking the person who is making the argument, rather than the validity of the argument itself. � “Who cares if the French oppose invading Iraq; they haven’t won a war in centuries!” http: //www. youtube. com/watch? v=an. Kk. X 1 wvg. Bw

Circular Reasoning � You state your claim and then, usually after rewording it, you

Circular Reasoning � You state your claim and then, usually after rewording it, you state it again as your reason. � Marijuana is injurious to your health because it harms your body. http: //www. youtube. com/watch? v=6 CGy. ASDj. E-U

Non Sequitur and Red Herring � “It does not follow” � There is no

Non Sequitur and Red Herring � “It does not follow” � There is no evident connection between a claim and its reason. � Also, using a diversionary tactic so as not to answer the question. � I don’t deserve a B for this course because I am a straight-A student. http: //www. youtube. com/watch? v=lj 3 i. Nx. Z 8 Dww

Slippery Slope � Arguing from the perspective that one change inevitably will lead to

Slippery Slope � Arguing from the perspective that one change inevitably will lead to another. � “If I extend your curfew tonight, you’ll go out and drink, and then you’ll be tempted to do this every night, and, eventually, you’ll become an alcoholic” http: //www. youtube. com/watch? v=TFJAe 9 sn. WDg