Logical(Fallacies(

Is(Your(Argument(Vulnerable?(

What is a LOGICAL Fallacy?

•  As(you(are(determining(what(evidence(to(use(

for(your(argument,(consider(logical'fallacies'(def:(potenAal(vulnerabiliAes(or(weaknesses(in(

logic(that(weaken(message).(((

•  They(oFen(arise(from(a"failure"to"make"a"logical"connec0on(between(the(thesis(and(the(evidence(used(to(support(it.(

Common and Believable

•  First,(logical(fallacies(are(very,(very(common(

and(can(be(quite(persuasive,(at(least(to(the(

casual(reader(or(listener.((

•  You(can(find(dozens(of(examples(of(flawed(

reasoning(in(newspapers,(adverAsements,(and(

other(sources.((

Ad hominem (Attacking the person)(• This(fallacy(occurs(when,(instead(of(

addressing(

someone's(argument(

or(posiAon,(you(

irrelevantly(aMack(

the(person(or(some(

aspect(of(the(person(

who(is(making(the(

argument.((

• The(fallacious(aMack(can(also(be(direct(to(

membership(in(a(

group(or(insAtuAon.(

Either-Or Fallacy / False Dilemma / Dichotomy

• When(you(reason(from(an(

eitherOor(posiAon(and(you(

haven't(considered(all(

relevant(possibiliAes.((

• These(can(be(well(intenAoned(but(a(logical(

fallacy(nonetheless.((

• A(fallacy(in(which(the(speaker(presents(two(

extreme(opAons(as(the(

only(possible(choices.(

“They"say"we"can"go"there"for"Thanksgiving"or"they"can"cut"us"out"of"the"will.""Our"choice.”"

Hasty Generalization(• This(fallacy(occurs(when(we(we(make(a(generalizaAon(on(the(

basis(of(insufficient(evidence.(

• This(may(occur(when(we(rely(on(too(small(of(a(sample(or(an(

unrepresentaAve(sample(to(support(the(generalizaAon.(

*You(should(be(especially(alert(to(the(fallacy(of(hasty(

generalizaAon(when(your(read(reports(and(studies(of(any(

kind.(

“Because"my"Honda"broke"down,"then"all"Hondas"must"be"junk.”"

Slippery Slope(• This(fallacy(describes(an(argument(that(portrays(today’s(

Any(misstep(as(tomorrow’s(slide(into(disaster.(

• A(slippery(slope(argument(becomes(wrongheaded(when(a(

writer(exaggerates(the(likely(consequences.(

• They(are(also(used(as(scare(tacAcs.(

“Today(late(for(ten(minutes,(

tomorrow(late(for(an(hour,(

and(then(someday(you(will(

simply(cease(to(show(up.”(

Red Herring(

This(occurs(when(a(speaker(skips(to(a(new(and(irrelevant(topic(

in(order(to(avoid(the(topic(of(discussion.((

Straw Man Fallacy(

• This(fallacy(occurs(when,(in(aMempAng(to(refute(another(person's(

argument,(you(address(only(a(weak(or(distorted(version(of(it.((

• Straw(person(is(the(misrepresentaAon(of(an(opponent's(posiAon(or(a(

compeAtor's(product(to(tout(one's(own(argument(or(product(as(

superior.((

• This(fallacy(occurs(when(the(weakest(version(of(an(argument(is(

aMacked(while(stronger(ones(are(ignored.(

“How"can"you"convict"this"man"of"murdering"his"mother?"He’s"an"Orphan!”"