Recognizing arguments Kareem Khalifa Department of Philosophy Middlebury College
QUIZ • Complete This Sentence: A deductive argument is valid when,…. • Read the following argument: • If it’s raining, then the streets are wet. • It’s not raining. • So the streets are not wet. The preceding argument is an example of • Modus ponens • Modus tollens • Hypothetical pollen • None of the above
Overview • Why this matters • Six Tips for Recognizing Arguments
Why this matters • Recognizing arguments is necessary for understanding a text. • You should also write so as to make your arguments easily recognizable.
6 strategies for recognizing arguments: overview • Look for premise and conclusion indicators • Use the question and answer test • Look for common argument forms • Balance faith and charity • Look for implicit argument-parts • Use your context
Strategy 1: Look for Indicators • These are phrases that flag conclusions and premises. • Ex. Since instilling democratic values is the only way to bring peace to the Middle East, we should make sure that Palestinians have the ability to participate in the policy decisions affecting them. • Ex. Instilling democratic values is the only way to bring peace to the Middle East, so we should make sure that Palestinians have the ability to participate in the policy decisions affecting them.
Warning! • Ex. SinceI woke up, I’ve worked out, prepared my lecture, and thenfinally, I walked to campus. • Lesson #1: Not every instance of these words is an indicator. • Lesson #2 (More General): None of these strategies are failsafe. But in total, they’re highly reliable in detecting arguments.
Strategy 2: Use the question and answer test • All arguments arise in response to some issue. An issue can always be expressed as a yes-or-noquestion. • Ex. Should we make sure Palestinians can participate in policy decisions affecting them? • The conclusion is an answer to that question. There is no yes-or-no question to which the descriptions, instructions, and other non-arguments would provide good (direct) answers. • Of course, they do provide potential answers to other kinds of questions, e.g., “How does a keyboard work?” or “How do you tie a bowtie?”
Strategy 3: Common Argument Patterns • This is the most important strategy if you want to go from recognizing an argument to analyzing/paraphrasing it. • General idea: • There are five very common, deductively valid argument patterns. • If a passage fits one of these patterns, then you know/recognize that the passage contains an argument.
1. Modus Ponens • If you exercise, then you’ll live longer. • You exercise. • So, you’ll live longer. P = You exercise. Q = You’ll live longer. If P then Q P So, Q
2. Modus Tollens • If you study hard, then you earn an A. • You didn’t earn an A. • So, you didn’t study hard. P = You study hard. Q = You earn an A. If P then Q Not-Q So, Not-P.
3. Hypothetical syllogism • If your parents love you, then someone loves you. • If someone loves you, then you won’t be a turd. • So, if your parents love you, then you won’t be a turd. P = Your parents love you. Q = Someone loves you. R = You won’t be a turd. If P, then Q. If Q, then R. So, if P, then R.
4. Disjunctive Syllogism • You take Logic in the Fall or you take Logic in the Spring. • You don’t take Logic in the Spring. • So, you take Logic in the Fall. P = You take Logic in the Fall Q = You take Logic in the Spring. P or Q Not-Q So, P.
5. Instantation/Categorical Syllogism • All professors are educated. • Khalifa is a professor • So, Khalifa is educated. F = is a professor. G = is educated. a = Khalifa All F’s are G’s. a is an F So, ais G.
Strategy 4: Balance faith and charity • Try to be as faithful to the author’s intentions as possible. Did he/she intend this as a premise/conclusion or was this merely an aside or tangent? • Try to be as charitable to the author as possible, i.e., try to interpret his/her argument as compellingly (i.e., as close to being valid) as possible without massively violating the faithfulness guideline.
More on faith and charity • As an elite institution of higher learning, Columbia University should be committed to pursuing the truth. Mahmoud Ahmedinejad has ambitions of waging a nuclear Jihad on the U.S. and its allies. So Columbia never should have invited that Holocaust denier to speak. • Is waging war antithetical to truth? • Is a “nuclear Jihad” the most neutral way to frame Ahmedinejad’s intentions? • As an elite institution of higher learning, Columbia University has an obligation to both pursue the truth and to respect certain ethical norms, including the promotion of international peace. As a Holocaust denier and a person who has threatened to use nuclear arms against the U.S. and its allies, Ahmedinejad would appear antithetical to both of these norms. Therefore, Columbia University should not have invited him to speak.
Strategy 5: Look for implicit argument-parts • Derivative of the “faith and charity” strategy. • What would be needed to make the passage fit into a common argument pattern?
More on implicit argument-parts • Both premises and conclusions can be implicit. • Ex. I checked to see if the door was locked before I left. You have nothing to worry about. • Hidden Premise: If I checked to see if the door was locked, then you have nothing to worry about. • Ex. Why would you ever go that restaurant? Their service is horrible, the food is disgusting, and the ambience is dreadful! • Hidden Conclusion: You should not go to this restaurant. • Enthymemes: arguments involving unstated propositions
Strategy 6: Use your context • Use context and background information to identify the issue, conclusion, and premise(s). This is especially helpful in: • Making vague terms, elliptical terms, and pronouns more transparent and precise; and • Using connotations and additional information to indicate what is at issue. • Identifying propositions not stated in declarative form. • This is also derivative of the faith and charity strategy
Recap • 6 Strategies for Recognizing Arguments • Look for premise and conclusion indicators • Use the question and answer test • Look for common argument forms • Balance faith and charity • Look for implicit argument-parts • Use your context • Using these strategies will help you read more effectively and write more clearly.
Exercises: 1.a. Anne Example p = Anne knows that she should take out the trash tomorrow. q = Anne will take out the trash tomorrow. If Anne knows that she should take out the trash tomorrow, then she will take out the trash tomorrow. Anne will not take out the trash tomorrow. Therefore, Anne does not know that she should take out the trash tomorrow.
1.b. Tom Example p = Tom makes his double chocolate cake. q = The dinner party will be a success. r = The guests will be happy. • If Tom makes his double chocolate cake, then the dinner party will be a success. • If the dinner party is a success, then the guests will be happy. • Therefore, if Tom makes his double chocolate cake, then the guests will be happy.
1.c. Beth Example P = Beth takes Calculus. Q = Beth takes Basic Painting. • Either Beth takes Calculus or Beth takes Basic Painting. • Beth does not take Basic Painting. • Therefore, Beth takes Calculus.
2. Build your own arguments @Middlebury
3.a. Because you didn’t order soup, you must have ordered salad. DISJUNCTIVE SYLLOGISM Either you order soup or salad. You didn’t order soup. So you ordered salad.
3.b. Anyone who believes that personhood begins at conception is against abortion. So Paul Ryan is against abortion. INSTANTIATION All who believe that personhood begins at conception are against abortion. Paul Ryan believes that personhood begins at conception. So, Paul Ryan is against abortion.
3.c. • If you leave that wound untreated, it will get infected. That could lead to gangrene. • HYPOTHETHICAL SYLLOGISM • If you leave that wound untreated, then that wound will get infected. • If that wound gets infected, then you could get gangrene. • If you leave that wound untreated, then you could get gangrene.
3.d The Red Sox won’t win the American League East this year. So the Yankees will. DISJUNCTIVE SYLLOGISM Either the Red Sox will win the AL East or the Yankees will win the AL East. The Red Sox will not win the AL East. So the Yankees will win the AL East.
3.e. • Live life to the fullest, as every day could be our last. • MODUS PONENS • If every day could be our last, then we should live life to the fullest. • Every day could be our last • So, we should live life to the fullest.