101 - L1 - Introduction to the Course

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PHI 101Professor D ouglas W. Portmore

Lecture 1 Introduction to the C ourse

Copyright 2012 by D ouglas W. Portmore

Last Updated: 2:10 PM on December 22, 2013

1. About the PowerPoint Presentations

Redacted versions of these p resentations ar e ava ilable u nder L ecture O utlinesin Blackboard.

Some words an d phrases have been redacted from these lecture ou tlines. Theseare n oted in the l ecture o utlines by [Redacted] a nd in the [powerpoint

[presentation] by underlining.

To get the red acted portions of the l ecture ou tlines, you must come t o class. Ifyoure ab sent, I suggest that you do one o r bo th the f ollowing: (1) ask one o fyour fellow students for hi s or h er notes and /or ( 2) come see m e or on e of the

TAs for hel p answering any of the study guide or Bl ac kb oard test questions thatyou cant answer due to your absence. We ar e al so ha ppy to sho w you the slidesthat you missed during office hours. Note, however, that we d o not, under anycircumstances, distribute u n-redacted versions of the Po werPoint presen tations.


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2. Continued

When taking notes, you should do m ore t han just ll in the r edacted words andphrases. After al l, these l ecture o utlines a re o nly outlines , which ar e m eant to

guide y ou in taking notes, not t o substitute f or yo ur t aking notes.

At the en d of eac h lecture o utline i s a st udy guide. These s tudy guides c ontainthe sh ort-answer qu estions f rom which I will select a su bset to appear on theexams. And there i s a B lackboard Test corresponding to each lecture. These t estscontain multiple cho ice qu estions. Some of the q uestions on the exam will bemodeled after these. You should work through both types of questions as weproceed through the lectures.

Always be p repared to start on the n ext lecture. I often switch to a n ew lecture i nthe m iddle o f a cl ass sess ion.

See the syl labus f or w hich assigned readings ar e rel evant to which lectures an ddo the rel evant readings p rior to the st art of that lecture. I do not announcewhen the read ings ar e d ue. You should take res ponsibility yourself for d oing theassigned readings for the n ext lecture as w e n ear t he en d of a gi ven lecture.

3. Overview*

In this l ecture, I explain the t heme f or t he co urse, specify what I hope f or yo u toget out of the co urse, and give you a b rief primer on logic an d critical thinking.

4. The Theme for the Course

*Most of you, as well as common opinion, are/is mistaken about the an swers to

the foregoing important questions.

*And even if youre n ot mistaken, not entitled to being condent in your answersat least, not before g iving these i ssues a l ot more t hought.


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5. What do you believe?

1. Does God exist?

2. Do we have f ree w ill?

3. Is i t possible ( not just physically possible, but possible i n the w idest sense o fpossible) for you to survive t he d eath and destruction of your physical body?

4. Is each of us bot h a m ind/soul and a p hysical body?

5. Assuming t hat it is r easonable for yo u to believe t hat you have an immortal soul andthat this s oul is t he su bject of your consciousness, could it then be reaso nable for youto anticipate h aving conscious exp eriences af ter t he d eath and destruction of yourphysical body?

6. Do you have kn owledge o f an external world, a w orld that exists independently ofyour perc eiving it? D o you know, for i nstance, that someone i s u p at the f ront of t heroom speaking?

7. Do you know that you exist?

6. What Ill be argu ing

*In this cou rse, Ill be arg uing (1) that God does n ot exist, (2) that we d o not havefree w ill, (3) that we are n ot both a m ind/soul and a p hysical body, (3) that it isnot possible for you to su rvive t he d eath and destruction of your physical body,(4) that it could not be reaso nable for you to a nticipate h aving consciousexperiences af ter t he d eath and destruction of your p hysical body, even if it werereasonable for yo u to believe b oth that you have an immortal soul and that thissoul is t he su bject of you r c onsciousness, (5) that we d o not have k nowledge of anexternal world, and (6) that you do n ot know that you exist.


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*The p ositions ar gued for i n this cou rse ar e n ot necessarily the v iews of yourprofessor. (I endorse on ly one of the abo ve si x. I would deny most and amundecided about a cou ple.) Indeed, I wont even be con sistent in the p ositionsthat I argue f or i n this cou rse. For i nstance, Ill presuppose t hat you have

knowledge o f an external world in one lecture an d then argue t hat you dont havesuch kn owledge in another.

7. Why is t his t he t heme?What is t he p oint?

*The p oint is t o challenge y ou to t hink, and to think hard, about your mostfundamental beliefs. So Im going to be p rovocative, because t he w hole p oint is

to provoke yo u to think.

*This i s al l just an exercise i n critical thinking. The p oint is t o foster t he st udentsabilities t o think critically, to argue co gently, to assess arg uments, to analyzecomplex i ssues, to understand abstract concepts, to attend to importantdistinctions, and to articulate v arious p ositions i n clear, precise, andunambiguous p rose. The p oint is al so t o instill in you the d isposition to questionorthodox opinion and, thus, to think for you rself.

*We cou ld perform this exer cise by reading, writing, and thinking about othermore m undane topics. But my h ope is that the topics that Ive ch osen will beconsiderably m ore t hought-provoking an d are in fact some of the m ost importantquestions t hat there are.

*I will try to ex plain why these q uestions ar e important and explain how we canmake p rogress in answering them. And the course w ill help you to h one theskills t hat you need to be ab le t o answer t hese q uestions.


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8. Whats an argument?

*http://www.youtube.com/watch?v=kQFKtI6gn9Y

9. Continued

*An argument doesnt have to be a goo d one.

*An argument isnt the sam e as con tradiction.

*Argument is an intellectual process. Contradiction is just the au tomatic

gainsaying of anything t he ot her person says.*

An argument is [a co nnected series o f statements i ntended to establish adenite proposition] .

*Note the use of the word [intended] . Whats i ts p urpose?


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10. A little b it of logic: Arguments

*Which, if any, of the f ollowing are t rue?

An argument is just the au tomatic gai nsaying of anything the ot her personsays.

In order to argue w ith someone, one m ust adopt the con trary position.

An argument is a set of two or more statements, one of which follows fromthe others.

An argument is a set of two or more statements, one of which p urports to

follow from the ot hers.

None.

*Answer: [B, D] .

*Our official denition: X is an a rgument if and only if X consists in two or m orestatements, one of which p urports to follow from the ot hers. Note h ow thisdiffers from the d enition of a go od argument

*The o ne t hat supposedly follows f rom the o thers i s cal led the conclusion , and thestatements t hat supposedly support the co nclusion are cal led premises .

11. Some Examples

*Consider t he following dialogue. Smith: Youre an idiot. Jones: No, I am not.

Besides, youre an ass. Smith: Well, at l east, I dont smell like o ne.*

Is t his an argument?

*[No]


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*What about the following? Since all dogs ar e m ammals and all mammals areanimals, all dogs m ust be an imals.

*[Yes]

*And what about this? Ive h ad two p hilosophy professors and theyve b oth beenmale. Therefore, all philosophy professors are m ale.

*[Yes] .

*And this? Theres no good reason to believe t hat God exists. So one sho uldnt

believe that God exists.

*[Yes] .

12. Statements

*A statement is a d eclarative sentence o r i ndependent clause. Suchsentences/ clauses ar e t ruth-assess able. In other w ords, a st atement is a s entenceor i ndependent clause ( e.g., 'the sk y is b lue') of the t ype t hat c an have a t ruth

value ( that is, of the t ype t hat can be ei ther t rue o r f alse). X is a st atement if andonly if X is a d eclarative sentence o r independent clause an d is, thus, truth-assessable.

*Give me an exam ple of a statement.You called on me.

*Give m e an example o f a sen tence i n English t hat isnt a st atement.Go to Bed

*It is t ruth-assessab ility that d ifferentiates st atements f rom non-statements, suchas c ommands, questions, and exclamations.


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13. Continued

*Which a re, and which are no t, statements?

*What time i s i t?

*[No] .

*Its Su nday.

*[Yes] .

*Sit up straight.

*[No] .

*Mozart was a bet ter musician than Barry Manilow was.

*[Yes] .

14. Continued

*Abortion is wrong.

*[Yes] .

*Crap!

* [No] .

*Doug philosophizes.

*[Yes] .


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*Squares have t hree si des.

*[Yes] .

* The w orld will end in 2099.

*[Yes] .

15. Propositions

*A proposition is a t ruth or a f alsehood that can often be exp ressed by a n umberof different, but logically equivalent, statements. Two statements exp ress t hesame p roposition if and only if they h ave exact ly t he same m eaning an d, thus,always h ave t he sam e t ruth value. (Note t hat a st atement is n ot a p roposition. Astatement expresses a proposition.)

*Do t he following p airs exp ress t he same p roposition?

*(a) Smith is f allible. Smith is n ot infallible.

*[Yes] .

*(b) Bill is m arried. Bill has a wife.

*[No] .

*(c) Fred is u nhappy. Fred is no t happy.

*[No, is an em otion vs l ack of e motion] .


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16. Continued

*(d) Today i s Su nday. Today is t he d ay after Saturday.

*[Yes] .

*(e) C hris i s a b rother. Chris i s a male si bling.

*[Yes] .

*(f) Chris i s an uncle. Chris h as a n ephew or a n iece.

*[No] .

*(g) Bill is a bachelor. Bill is si ngle.

*[No] .

17. Validity

*A valid ar gument is on e in which t he t ruth of the p remises guarantees t hat theconclusion will be t rue. More p recisely, an argument is va lid if and only if, in nopossible w orld, are al l its p remises t rue an d its con clusion false. Arguments t hatare n ot valid are invalid . (Note t hat only arguments, and not statements orpropositions, can be p roperly called valid or i nvalid. By contrast, only statementsand propositions, not ar guments, can be p roperly called true o r f alse.)

*Does a val id argument have to have true p remises? No

* Does a val id argument have t o have a t rue concl usion? No

*Can an invalid argument have t rue p remises and a false c onclusion? Yes

*So whats t he o ne com bination thats impossible?


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*Answer: [Valid argument with true p remises and a f alse c onclusion] .

*X is a v alid argument if and only if it is l ogically impossible f or al l its p remises t o

be true while its conclusion is false.


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18. Continued

*Is t he following a v alid argument:

*P1) If Bob studies h ard, he w ill get an A.

*P2) Bob w ill get an A.

*C) Therefore, Bob studies ha rd.

*[No] .

*Is t he following a v alid argument?

*P1) All professional body builders ar e sm art.

*P2) DWP is a p rofessional body builder.

*C) Therefore, DWP is smart.

* [Yes] .

19. Continued


*P1) All dogs are mammals.

*P2) Some mammals are heavi er than a t en-ton truck.

*C) Therefore, some d ogs ar e h eavier than a t en-ton truck.

*[No] .


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20. Continued


*P1) If today i s M onday, then Bill is no t where h es s upposed to be.

*P2) Yesterday was Sunday.

*C) So Bill is no t where h es s upposed to b e.

*[Yes] .


*P1) Either I just saw a chi mp in downtown Manhattan or I ve go ne insane.

*P2) Im perfectly sane.

*C) So I just saw a chimp in downtown Manhattan.

* [Yes] .

21. Some Common Valid Argument Forms

* Modus Ponens

*P1: If P, then Q.

*P2: P.

*C: Therefore, Q.


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*Let me exp lain why it is l ogically impossible for this t o have t rue p remises and afalse conclusion

* Modus Tollens

*P1: If P, then Q.

*P2: ~Q. (Let ~Q stand for it is n ot the ca se t hat Q .)

*C: Therefore, ~P.

* Tautology

*P1: Either P or P.

*C: Therefore, P.

22. Some more

* Disjunctive Syllogism

*P1: Either P or Q .

*P2: ~P.

*C: Therefore, Q.

* Hypothetical Syllogism

*P1: If P, then Q.

*P2: If Q, then R.

*C: Therefore, if P, then R.


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* Constructive Dilemma

*P1: Either P or Q .

* P2: If P, then R.

*P3: If Q, then S.

*C: Therefore, either R or S.

23. And some more

*P1: All Xs ar e Ys.

*P2: F is X.

*C: Therefore, F is Y.

* P1: No X is Y.

*P2: F is X.

*C: Therefore, F is n ot Y.


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24. Two Common Invalid Argument Forms

*Affirming the Consequent

*P1: If P, then Q.

*P2: Q.

* C: Therefore, P.

*Denying the Antecedent

*P1: If P, then Q.

*P2: ~P.

* C: Therefore, ~Q.

25. Demonstrating that an Argument Is I nvalid

*We Do So by Constructing a Counterexample:

*An argument that results f rom uniformly replacing the cap ital letters i n anargument form with statements i s c alled a substi tution instance of that form.


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26. Continued

*A counterexample to a n argument is a s ubstitution instance of its form in whichthe p remises are al l true a nd the co nclusion is f alse. Since v alidity and invalidity

is a m atter of form and since on ly an invalid argument can have t rue p remisesand a false conclusion, a cou nterexample to an argument proves both that it andits f orm are i nvalid.

*X is a cou nterexample t o an argument if and only if X is a su bstitution instance ofits form in which all the p remises ar e t rue an d the co nclusion is false.

27. To construct a co unter-example

*Follow these st eps:

1. Identify the form of t he argu ment.

2. Find new statements t hat, if substituted for t he ca pital letters i n the co nclusion of theargument form, produce a well-known falsehood. Substitute t hese st atements f or t herelevant capital letters uniformly throughout the argu ment form.

28. Continued

3. Find additional statements t hat, if substituted uniformly for t he rem aining capitalletters i n the argu ment form, produce p remises t hat are well-known t ruths.

29. An example of constructing a cou nterexample

*Denying the Antecedent

*P1: If P, then Q. True

*P2: ~P. True


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* C: Therefore, ~Q. False

*To produce a counterexample, we need C to be false. So what does Q need t o be?

* [true]

*To produce a counterexample, we need P2 to be true. So what does P need to be?

*[false]

*To produce a counterexample, we need P 1 to be t rue. So we need an example ofIf P, then Q that i s t rue, where P is f alse an d Q is t rue.

*Examples: (1) If Gore i s t he U .S. President, then Gore i s a U .S. citizen. (2) If DWPhas an M.D., then DWP has a d octorate. (3) If Schwarzenegger was born in theU.S., then Schwarzen egger is a U .S. citizen.

30. Continued

*So the f ollowing substitution instances c onstitute co unterexamples t o the ab oveargument form: (1) P = Gore i s t he U .S. President; Q = Gore i s a U .S. citizen. (2) P= DWP has an M.D.; Q = DWP has a doctorate. (3) P = Schwarzenegger was bornin the U .S.; Q = Schwarzenegger is a U .S. citizen.

*But these d ont: (A) P = Obama i s t he U.S. President; Q = Obama i s a U .S. citizen.(B) P = DWP has a Ph.D.; Q = DWP has a doctorate. (C) P = Obama is a U.S.citizen; Q = Obama w as born in the U.S.

31. Testing Your Understanding

*Which, if any, of the following substitution instances c onstitute cou nterexamplesto the following form?

*P1: If P, then Q.


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*P2: P.

*C: Q?

* (a) P = Gore i s t he U.S. President; Q = Gore i s a U .S. citizen. (b) P = DWP has aPh.D.; Q = DWP has a d octorate. (c) P = Schwarzenegger was born in the U.S.; Q= Schwarzenegger i s a U .S. citizen. (d) P = Obama i s t he U.S. President; Q =Obama i s a U .S. citizen. (e) none of the above.

32. One more

*Which, if any, of the following substitution instances c onstitute cou nterexamplesto the following form?

*P1: If P, then Q.

*P2: ~Q.

*C: ~P?

*(a) P = Gore i s t he U.S. President; Q = Gore i s a U .S. citizen. (b) P = DWP has aPh.D.; Q = DWP has a d octorate. (c) P = Schwarzenegger was born in the U.S.; Q= Schwarzenegger i s a U .S. citizen. (d) P = Obama i s t he U.S. President; Q =Obama i s a U .S. citizen. (e) none of the above.

33. Soundness

*An argument is sound if and only if it both is val id and has o nly true p remises.

*Is the following a sou nd argument?

*P1) All humans are mammals.

*P2) DWP is a human.


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*C) Therefore, DWP is a mammal.

*[Yes] .


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34. Continued

*And this one?

*P1: If Barak Obama i s m arried, then he i s no t a b achelor.

*P2: Barak O bama is married.

*C: So Barak Obama is not an unmarried man.

*[Yes] .

*Are all sound arguments valid?

*Are all valid arguments sound?

*What do we know about the conclusion of a sound argument? Always true

35. Deductive versus I nductive

* A deductive ar gument is on e i n which the t ruth of its p remises purports t oestablish that i ts co nclusion is ce rtainly true.

*An inductive argument is on e i n which the t ruth of its p remises purports t oestablish that i ts co nclusion is p robably true.

36. Strength and Cogency

*An argument is strong if and only if the t ruth of its p remises m akes i ts con clusionmore l ikely true t han false. The m ore p robable i t makes t he t ruth of itsconclusion the stronger t he inductive argu ment is. Inductive a rguments that arenot strong are weak .

*An argument is cogent if and only if it both is s trong and has o nly true p remises.


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*Are al l valid arguments s trong?

*Are al l valid arguments cogent?

* Are al l sound arguments strong?

*Are all sound argument cogent?

37. Which ar e strong? And which ar e cogent?

*P1: Murder an d killing in self-defense are a like i n all morally relevant respects.P2: Murder i s m orally wrong. C: Therefore, killing in self-defense i s m orallywrong.

*[Strong, Not c ogent] .

*P1: Everyone w ith the last name Portmore t hat I know of is a ph ilosophyprofessor. C: Therefore, everyone w ith the l ast name Portmore i s a p hilosophyprofessor.

* [Weak and not cogent] .

*P1: Crest toothpaste i s t he m ost popular b rand of toothpaste. C: Therefore, Cresttoothpaste i s t he m ost effective at ghting cavities.

*[Weak, and not cogent] .


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38. Continued

*P1: The Channel 9 weatherman has predicted that Phoenix will be h it by acategory 5 h urricane t omorrow. P2: His p redictions ar e accu rate 95% of t he t ime.

C: Therefore, Phoenix w ill be h it by a cat egory 5 h urricane tomorrow.

*[Inductive, Strong, not cogent] .

*P1: Every day of my life so f ar t he su n has r isen in the east . P2: Tomorrow is i nthe rel evant respects j ust like a ll those o ther d ays. C: Therefore, the su n will risein the east tomorrow.

*[Inductive, Strong, cogent] .

*P1: All lizards are rep tiles. P2: Geckos are l izards. C: Therefore, geckos arereptiles.

*[Deductive, Strong, and Cogent] .

39. Flow Chart on Assessing Arguments

Do the p remises purport to e stablish tha t the con clusion is certainly true?

Yes: Deductive No: Inductive

Do the p remises provide go od grounds for ac cepting the conclusion?

Yes: Valid & Strong No: Invalid & Unsound Yes: Strong No: Weak & NotCogent


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Are al l the p remises true?

Yes: Sound & Cogent No: Unsound and Not Cogent Yes: Unsound but Cogent No:

Unsound and Not Cogent

40. Some examples

*Say whether t he f ollowing arguments ar e d eductive o r i nductive, valid or i nvalid,sound or un sound, strong or weak, cogent or no n-cogent.

*P1) Every time I ve seen D oug teaching, Doug is w earing a t ie.

*C) Therefore, Doug always w ears shorts w hen he teaches.

*This i s ar gument is [Inductive, Invalid, Unsound, Weak, non-cogent] . (Imassuming that youve seen m e t each o nly a few times.)


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41. More examples

*P1) All dogs are mammals.

*P2) All mammals are animals.

*C) Therefore, all dogs ar e an imals.

*This argument is [Valid Strong D eductive, Cogent, Sound] .

*P1) The weatherman has pre dicted that theres a 90% chance of a cat egory 5hurricane h itting P hoenix today.

*P2) The weatherman predictions ar e al most always ac curate.

*C) Therefore, a cat egory 5 hurricane w ill hit Phoenix t oday.

*This argument is [Inductive Strong, invalid, unsound, non cogent] .


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42. More examples

*P1) Either D oug is t he b est teacher or he i s t he w orst teacher.

*P2) Its n ot the case t hat Doug is t he w orst teacher.

*C) Therefore, Doug is t he b est teacher.

*This argument is [Deductive, Valid, Strong, Unsound, non cogent] .

*P1) I f God exists, then theres an objective moral standard.

*P2) God does no t exist.

*C) Therefore, there i s n o objective moral standard.

*This argument is [Deductive, Not Valid weak u nsound and non cogent] .

43. Three Ways an Argument Can Go Wrong

*(1) The p remises, even if true, do not provide g ood grounds for accepting theconclusion. That i s, the a rgument is n either val id nor s trong.

*Example: P1) All mammals are an imals. P2) Some an imals ar e reptiles. C)Some mammals are reptiles.

*(2) We sh ould not accept all the p remises.

*Note i t could be t hat we should not accept a p remise e ven though it istrue, for we m ay not have g ood evidence for t hat premise d espite i ts bei ngtrue. So one reason not to a ccept a p remise is t hat we h ave su fficientreason to believe t hat it is f alse. But another r eason not to accept a p remiseis t hat w e h ave insufficient reason to believe t hat it is t rue.


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*Example: P1) Fl uffy (Dougs i nvisible, intangible, inaudible, odorless,avorless p et bunny rabbit) exists. P2) I f Fluffy exists, then some a nimalsare i nvisible. C) Some a nimals are i nvisible.

* (3) One or m ore of the p remises beg t he q uestion. That is, one or m ore of thepremises presuppose t hat the con clusion is t rue. Thus, the argu ment involvescircular rea soning.

*Example:P1) The Bible is Gods word. P2) If the Bible is Gods word, theneverything it says i s t rue. P3) The Bible say s G od exists. C) God exists.

44. Transition

*Okay, thats eno ugh formal logic for n ow.

*Pretty soon, well put these con cepts an d methods into practice. Thats w hen itgets i nteresti ng.

*But before w e get to the p hilosophical stuff, let me say w hat I expect you to getout of t he co urse.

45. What You Should Get out of the Course

*Recall that the t heme o f the co urse i s t hat virtually everything you think that youknow you dont know and that much of what you believe to be true is false.

*Now the p oint of the co urse i s n ot to convince yo u that your beliefs ar e f alse, butrather to co nvince yo u that you need to think about them critically and with an

open mind.

46. Continued


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*So the p oint of the co urse i s t o (1) convince yo u that you need to think criticallyabout some important and fundamental questions, (2) demonstrate to you that itis p ossible t o make p rogress in this end eavor, and (3) teach you some o f thecritical thinking skills t hat youll need to make p rogress in this an d other

endeavors.

47. Continued

*The p oint of the cou rse i s no t to impart any factual knowledge ( of, say, whatDescart ess vi ews w ere), but to help you develop certain skills an d attitudes t hatyoull need to be a n excellent critical thinker.

* The m ain skill here is t he ab ility t o ev aluate an d construct arguments. And themain attitude h ere i s t hat of being willing to question your ow n beliefs as w ell asorthodox opinion.

*These ski lls an d attitudes w ill be o f great practical use t o you throughout yourlives.

48. Whats nex t?

*Next, we take u p the issue of whether God exists.

Study Guide for Lect ure 1

The exam s will be in-class exams. None of them are cumulative. Each exam willcover on ly the m aterial subsequent to the l ast exam or, in the case o f the rst

exam, subsequent to the st art of the sem ester.


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You are al lowed to refer to one 8. 5" x 11 " piece of paper with whateverhandwritten notes you want on it. All the n otes must be w ritten in your ownhandwriting. No typed notes are al lowed. Also, you are no t allowed tocollaborate w ith others in putting together t he i nformation that goes on to your

cheat sh eet. Lastly, if you ever quote m e o r anyone el se on a t est or a p aper, youneed to b e sure t o put the q uote in quotation marks. So be sure t o indicate o nyour cheat sheet whats a q uote an d whats no t. And, by the w ay, you dont getcredit for s imply quoting me or t he t ext. You need to sh ow that you understandthe qu ote by either putting things i n your own words or by p roviding examples.

You will need to bring all the following with you to the exam : (1) some N o. 2pencils an d (2) a p hoto ID. The cheat sh eet is op tional.

Continued

*On the exam there w ill be two t ypes of questions: multiple-choice qu estions andshort-answer qu estions. Youll nd examples of t he sort s of multiple-choicequestions you might see on exam in the Blackboard tests corresponding to therelevant lectures. All the p ossible sh ort-answer qu estions are t o b e found in thestudy guides at the en d of these l ecture o utlines. These sho rt-answer questionswill often be t aken verbatim from these s tudy guides. The o nly exceptions w ill becases w here I see t he n eed to rew ord a q uestion so as t o m ake it clearer or where

a p art of the q uestion appears i n triple b rackets: >. That part of t hequestion will probably not be t aken verbatim.

*Ive tried to design the t est so t hat it requires yo u think and doesnt require much

by way of memorization. Oftentimes, Ill give you the relthe qu estion so t hat you dont need to m emorize t hem.

*Also, I will try to word the exam questions so t hat you cant merely m emorize t heanswers to them. For instance, well be talking about a n umber of arguments in

the co urse ( such as t he a rgument from evil). In lecture, youll learn that there are certain premises that we sh ould not accept. To ensure t hat you dont justmemorize w hether i t is, say, P2 o r P3 that we sh ould not accept, Ill oftenrearrange t he or der of the p remises when I present them on an exam for you toevaluate.


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The Questions

*(1.1) (a) Provide an original example o f a st atement. (b) Provide an originalexample o f a n on-statement. [X is a st atement if and only if X is a d eclarative

sentence o r independent clause an d is, thus, truth-assess able.]

*(1.2) (a) Provide t wo original statements t hat express t he sam e p roposition. (b)Provide t wo original statements t hat do n ot express the sam e p roposition. [Twostatements exp ress the sam e p roposition if and only if they have ex actly the sam emeaning and, thus, always have t he same t ruth value.]

*(1.3) Provide an original example o f a v alid argument. [An argument is val id ifand only if, in no possible w orld, are a ll its p remises t rue a nd its con clusion false.

Arguments t hat are n ot valid are invalid .]*

(1.4) Provide an original example o f an invalid argument. [An argument is val idif and only if, in no possible w orld, are al l its p remises t rue a nd its con clusionfalse. Arguments t hat are n ot valid are invalid .]

*(1.5) Fi ll in the b lanks so that t he resu lting argument is v alid or, if this ca nt bedone, then circle t he f ollowing: not p ossible. [An argument is va lid if and only if,in no possible w orld, are al l its p remises t rue and its con clusion false. Argumentsthat are n ot valid are invalid .]

*

*(1.6) Fi ll in the b lanks so that t he resu lting argument is v alid or, if this ca nt be

done, then circle t he f ollowing: not p ossible. [An argument is va lid if and only if,in no possible w orld, are al l its p remises t rue and its con clusion false. Argumentsthat are n ot valid are invalid .]

*


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*C: Professor Portmore i s no t a rock star.>>>


*

* (1.8) Fi ll in the b lanks so that t he resu lting argument is v alid or, if this ca nt bedone, then circle t he f ollowing: not p ossible. [An argument is va lid if and only if,in no possible w orld, are al l its p remises t rue and its con clusion false. Argumentsthat are n ot valid are invalid .]

*


*

*(1.10) Give a n original example o f an argument that begs t he q uestion.


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*(1.11) Prov ide an original example o f an argument that is s trong but not valid or,if this can t be d one, then circle the following: not possible. [An argument is v alidif and only if, in no possible w orld, are al l its p remises t rue a nd its con clusionfalse. Arguments t hat are n ot valid are invalid . An argument is strong if and only

if the t ruth of its p remises m akes i ts con clusion more l ikely true t han false.]

*(1.12) Prov ide an original example o f an argument that is val id but not strong or,if this can t be d one, then circle the following: not possible. [An argument is v alidif and only if, in no possible w orld, are al l its p remises t rue a nd its con clusionfalse. Arguments t hat are n ot valid are invalid . An argument is strong if and onlyif the t ruth of its p remises m akes i ts con clusion more l ikely true t han false.]

Documents

101 - L1 - Introduction to the Course