LSAT Logical Reasoning PDF

Sufficient and Necessary Conditions Conditional reasoning - the broad name given to logical relationships composed of sufficient and necessary conditions ○ Any conditional statement consists of at least one sufficient condition and at least one necessary condition Sufficient condition An event or ci...

Sufficient and Necessary Conditions Conditional reasoning - the broad name given to logical relationships composed of sufficient and necessary conditions ○ Any conditional statement consists of at least one sufficient condition and at least one necessary condition Sufficient condition An event or circumstance whose occurrence indicates that necessary condition must also occur If a sufficient condition occurs, you automatically know that the necessary condition also occurs Necessary condition An event or circumstance whose occurrence is required in order for sufficient condition to occur If a necessary condition occurs, then it is possible but not certain that the sufficient condition will occur Any conditional relationship can always be reduced to an “if…then” form Ex: If someone gets an A+ on a test, then they must have studied for the test. - If the above statement is true, then anyone who receives an A= on a test must have studied for the test - Someone who studied might have received an A+, but it is not guaranteed - Since getting an A+ automatically indicates that studying must have occurred, the sufficient condition is “get an A+” and it follows that “must have studied” is the necessary condition. - When an author makes a conditional statement, he or sh believes that statement to be true without exception - So, then according to the author anyone who gets an A+ mst have studied (they may have done other things, but studying had to occur) Arrow Diagrams - For a basic conditional relationship, the arrow diagram has three parts: 1. A representation of the sufficient condition 2. A representation of the necessary condition 3. And an arrow pointing from the sufficient condition to the necessary condition Sufficient A+ Necessary → Study Three Logical Features of Conditional Reasoning 1. The sufficient condition does not make the necessary condition occur. That is, the sufficient condition does not actively cause the necessary condition to happen. Instead, in a conditional statement the occurrence of the sufficient condition is a sign or indicator that the necessary condition will occur, is occurring, or has already occurred. ○ In example, the occurrence of someone receiving an A= is a sign that indicates that studying must also have occurred. The A+ does not make the studying occur. 2. Temporally speaking, either condition can occur first, or the two conditions can occur at the same time. In example, the necessary condition (studying) would most logically occur first. Depending on the example, the sufficient condition could occur first. 3. The conditional relationship stated by the author does not have to reflect reality. Your job is not to figure out what sounds reasonable, but rather to perfectly capture the meaning of the author’s sentence Valid and Invalid Statements - When analyzing a basic conditional statement, there are certain observations that can be inferred from the statement and there are observations that may appear true but are not certain - Conditional reasoning occurs when a statement containing sufficient and necessary conditions is used to draw a conclusion based on the statement Taking our discussion example as undeniably true, consider the following statements: 1. John received an A+ on the test, so he must have studied for the test. * Valid - according to the statement because John received an A+, he must have studied for the test. We call this type of inference the Repeat form because the statement basically repeats the parts of the original statement and supplies them to the individual in question, John. 2. John studied for the test, so he must have received an A+ on the test * Invalid - Just because John studied for the test does not actually mean he received an A+. He may have only received a B, or perhaps even failed. To take statement 2 as true is to make an error known as a Mistaken Reversal. Sufficient Necessary Studyj → A+j The form here reverses the Study and A+ elements, and although the statement might be true, it is not definitely true. Just because the necessary condition has been fulfilled does not mean that the sufficient condition must occur. 3. John did not receive an A+ on the test, so he must not have studied for the test. * Invalid - Just because John did not receive an A+ does not mean he did not study. He may have studied but did not happen to receive an A+. Perhaps he received a B instead. To take this statement as true is to make an error known as a Mistaken Negation. Sufficient A+j Necessary → Studyj The form here negates the A+ and Study elements (this is represented by the red highlight), and although this statement might be true, it is not definitely true. Just because the sufficient condition has not been fulfilled does not mean that the necessary condition cannot occur. 4. John did not study for the test, so he must not have received an A+ on the test. * Valid - If studying is the necessary condition for getting an A+, and John did not study, then according to the original statement there is no way John could have received an A+. This inference is known as the contrapositive, and you can see that when the necessary condition fails to occur, the sufficient condition cannot occur. Sufficient Studyj Necessary → A+j The form here reverses and negates the study and A+ elements. When you are looking to find the contrapositive, do not think about the elements and what they represent. Instead, simply reverse and negate the two terms. * Table example on next page If someone gets an A+ on a test, then they must have studied for the test. Repeat Form Mistaken Reversal Mistaken Negation Valid John received an A+ Invalid John studied for the Invalid Contrapositive Valid John did not receive John did not study for on the test, so he must test, so he must have an A+ on the test, so the test, so he must have studied for the received an A+ on the he must not have not have received an test. test studied for the test. A+ on the test. Simply restates the elements in the original order they appeared. Switches the elements in the sufficient and necessary conditions, creating a statement that does not have to be true. Negates both conditions, creating a statement that does not have to be true. Both reverses and negates, it is as if two wrongs do make a right. For contrapositive simply reverse and negate the two terms. Sufficient Necessary Sufficient Necessary Sufficient Necessary Sufficient Necessary A+ → Study Studyj → A+j A+j → Studyj Studyj → A+j * There is a contrapositive for every conditional statement, and if the initial statement is true, then the contrapositive is also true. The contrapositive is simply a different way of expressing the initial statement. * Focus more on the form of the relationship and less on the content The Multiplicity of Indicator Words - Recognizing conditionality when it is present - One of the factors that makes identifying conditional statements difficult is that so many different words and phrases can be used to introduce a sufficient or necessary condition Examples of statements that are all diagrammed the same way: 1. To get an A+ you must study. 2. Studying is necessary to get an A+. 3. When someone gets an A+, it shows they must have studied. 4. Only someone who studies can get an A+. 5. You will get an A+ only if you study. To introduce a sufficient condition: To introduce a necessary condition: if then when only whenever Only if every must all required any unless each except In order to until People who without precondition Two Critical rules about how conditional reasoning appears in a sentence: 1. Either condition can appear first in the sentence. * In statements 1, 3, and 5 the sufficient condition appears first in the sentence; in 2 and 4 the necessary condition appears first. You cannot rely on encountering the sufficient condition first and instead you must keen an eye out for conditional indicators. 2. A sentence can have one or two indicators. * Sentences do not need both a sufficient condition indicator and a necessary condition indicator in order to have conditional reasoning present. The Unless Equation - In the case of “unless,” “except,” until,” and “without,” a two-step process is applied to the diagram: 1. Whatever term is modified by unless, except, until, or without becomes the necessary condition. 2. The remaining term is negated and becomes the sufficient condition. * When you encounter a stimulus that contains conditional reasoning and a Must Be True question stem, immediately look for a contrapositive or a repeat form in the answer choices. Conditional Linkage - If an identical condition is sufficient in one statement and necessary in another, the two can be linked to create a chain Example: Statement 1: A→B Statement 2: B→C Chain: A→B→C Inference: A→ C Contrapositive: A→ C * The “B” condition is common to both Statement 1 and 2, and serves as the linking point. Because all A’s are B’s, and all B’s are C’s, we can make the inference that all A’s are C’s. Diagramming Either/Or Statements * “either/or” is at least one of the two, possibly both. * Since at least one of the terms must occur, if one fails to occur then the other must occur. Example: Either John or Jack will attend the party. Proper Diagram: John → Jack Contrapositive: Jack → John * The two diagrams indicate that if John fails to attend the party, then Jack must attend, and if Jack fails to attend the party, then John must attend. * Diagrams reflect the fact that if one of the two fails to attend, then the other must attend in order to satisfy the “at least one of the two” conditions imposed by the either/or term. * Neither of these two diagrams preclude both John and Jack from attending the party. * For example, if John is in fact attending the party, this information automatically satisfies the either/or condition. But the information that John is attending the party does not affect Jack in the least. He is now free to attend or not attend the party as he chooses. Example: You are either in Los Angeles or San Francisco. Los Angeles → San Francisco San Francisco → Los Angeles * These diagrams indicate that if you are not in one of the cities, then you must be in the other city. But we also know that if you are in one of the cities, then you are not in the other. Los Angeles → San Francisco San Francisco → Los Angeles * These diagrams indicate that you are always in one of the two cities and in one city only. * Hence, if you are in one city, you are not in the other city Example: Either Cindy or Clarice will attend the party, but not both. Cindy → Clarice Clarice→ Cindy * There are ways for the test makers to indicate that the terms in the two conditions cannot both occur. Since the original statement also includes the phrase, “but not both,” this precludes the possibility of both attending the party, and the statement is also diagrammed as: Cindy → Clarice Clarice→ Cindy * Thus, it is true that one and only one of the two will attend the party. * If Cindy attends, Clarice will not attend, and if Cindy does not attend, Clarice must attend. * If Clarice attends the party, Cindy will not attend, and if Clarice does not attend the party, Cindy must attend. * Either/or, but not both means that exactly one of the two occurs. The Exception to the Rule: “Than Either” * When the phrase “than either” is used, the term “either” translates to both. Example: Desmond likes biology better than either Chemistry or Physics. * The meaning of this statement is that Desmond likes biology better than both chemistry and physics (individually, not combined). * Desmond likes biology better than he likes chemistry * Desmond likes biology better than he likes physics * Biology is Desmond’s favorite of the three. Example: Akio is taller than either of the other two boys on the team. * This statement means that Akio is individually the tallest of the three. Only, Only if, and The Only Example: The only way to become rich is to work hard. * In this example, “only” modifies “way” and “way” refers to “work hard” and thus the diagram is: Rich → Work Hard * So, if you see someone who is rch, then they must have worked hard. But is someone world hard, that does not necessarily mean they are rich, so “work hard” is not a sufficient condition. * “The only” is a sufficient condition indicator that modifies the condition that immediately follows it. * “Only” “only if” direct;y precede a necessary condition whereas “the only” directly precedes a sufficient condition Multiple Sufficient and Necessary Conditions Example: To graduate from Throckmorton College you must both be smart and resourceful. Two Necessary Conditions if you are to graduate from Throckmorton: 1. You must be smart 2. You must be resourceful Sufficient Graduate(t) Necessary → smart AND resourceful * Difficulty in handling multiple necessary conditions is with the contrapositive * If either one of the two necessary conditions is not met, then you cannot graduate from Throckmorton * It is not required that both necessary conditions fail to be met in order to prevent the sufficient condition from occurring Sufficient Necessary ~ Smart OR ~ resourceful → ~ Graduate(t) * Note that in taking the contrapositive, the “and” in the necessary condition is changed to “or”. * The reverse would be true if the necessary conditions had originally been linked by the term “or” Example: To graduate from Throckmorton College you must be smart or resourceful. Sufficient Graduate(t) Necessary → smart OR resourceful * In this case, to graduate from Throckmorton you only need to satisfy one of the two necessary conditions * This does not preclude the possibility of satisfying both conditions, but it is not necessary to do so Contrapositive: Sufficient Necessary ~ Smart AND ~ Resourceful → ~ Graduate(t) * This diagram indicates that if you are not smart AND not resourceful, then you cannot graduate from Throckmorton Example of statement with two sufficient conditions: If you are rich and famous, then you are happy. Sufficient Rich AND famous Necessary → happy * Note that you must be both rich and famous to meet the sufficient condition, and if you were both rich and famous then you would also have to be happy. Contrapositive: Sufficient ~ Happy Necessary → ~Rich OR ~famous * The contrapositive indicate that if you are not happy, then you are either not rich or not famous * Thus, if you are not happy, then you are not rich, not famous, or not both. Example: If you are rich or famous, then you are happy. Sufficient Necessary Rich OR famous → happy * Note that you can either be rich or famous, or both, to meet the sufficient condition Contrapositive: Sufficient ~ happy Necessary → ~rich AND ~famous * The contrapositive indicates that if you are not happy, then you are neither rich nor famous. * Thus, if you are not happy, then you are not rich and not famous The Double Arrow * There are some statements that produce arrows that point in both directions * These arrows, known as biconditionals, indicate that each term is both sufficient and necessary for the other * The double arrow indicates that the two terms must always occur together Example: Ann will attend if and only if Basil attends. * This sentence contains the conditional indicators “if” and “only if: connected by the term “and”. This creates two separate conditional statements: 1. “A if B” AND 2. “A only if B” The “A if B” portion creates: B→A The “A only if B” portion creates: A→B Combined, the two statements create: A↔B The only two scenarios are possible under this double arrow: 1. A and B both attend (A and B) 2. Neither A nor B attend (~A and ~B) * Any scenario where one of the two attends but the other does not is impossible * Terms in a double arrow relationship occur together or both do not occur The double arrow is typically introduced in any of the following three ways: 1. Use of the phrase “if and only if” or any synonymous phrase, including: - If but only if - Then and only then - Then but only then - When and only when - When but only when - All but only * Note that these phrases typically feature a sufficient condition indicator and a necessary condition indicator joined by “and” or “but.” 2. Use of the phrase “vice versa”: If A attends then B attends, and, and vice versa. 3. By repeating and reversing the terms: If A attends then B attends, and if B attends then A attends. The Double-Not Arrow Just as the double arrow indicates that two terms must occur together, the double-not arrow indicates that two terms cannot occur together The double-not arrow is the “not equal” sign of logic; the two terms at the end of the sign cannot be selected at the same time Example: If gomez runs for president, then Hong will not run for president. * If G runs for president, then H will not run for president * Via the contrapositive, we can also infer that if H runs for president then G will not run for president * This, of G or H runs for president, then the other will not run for president * The two can never run for president together G⇹H Possible scenarios that can occur: 1. G runs for president, H does not. (G and ~H) 2. H runs for president, G does not. (~G and H) 3. Neither G nor H runs for president. (~G and ~H) * The only scenario that cannot occur is both G and H running for president Nested Conditionals - Occur when an entries conditional relationship is used as a complete condition inside another conditional statement Example: If you want a table at this restaurant you have to wait, unless you have a reservation. * Indicators: If, have to, unless * Two of them are necessary: have to, unless Divide the sentence into two parts using the comma in the middle: If you want a table at this restaurant you have to wait, Unless you have a reservation. * We can see that the first clause is its own complete conditional statement First clause diagram: Table→Wait BUT, this clause was modified by “...unless you have a reservation”: * Unless introduces a necessary condition - in this case “reservation” * Thus the remainder is negated: (Table↦Wait)→Reservation * Parentheses helps us identify that the conditional element inside the parentheses is its own separate relationship * One relationship is “nested” inside the overall conditional statement * So, the conditional relationship between waiting for a table and getting one is subject to an exception modified by a necessary condition indicator “unless” * The “reservation” portion of the sentence serves as a way around the original relationship, where waiting for a table is no longer necessary, provided you satisfy the final condition of having a reservation * These statement typically occur when you have multiple conditional indicators of the same type in a sentence (as in, two necessary conditions), or multiple sentences all referring to the same conditions * Most often this occurs in situations involving an exception, and so the word “unless” (or a synonymous phrase) is typically one of the necessary indicators present * What is required to get a table? You can either wait or have a reservation! Since you only need to satisfy one of these two conditions to potentially get your table, we can write this statement as: Table→Wait OR Reservation EX: Let’s assume we want a table and omit that intent from our diagram, the following statement would be acceptable: ~Wait→Reservation ~Reservation→Wait Another example: To go to the movie premier you must have a ticket, unless you are on the VIP list. Movie Premier→ticket (Movie Premier↦ticket)→VIP Movie Premier→ticket OR VIP Conditional Reasoning Review * A sufficient condition can be defined as an event or circumstance whose occurrence indicates that a necessary condition must also occur. * A necessary condition can be denied as an event or circumstance whose occurrence is required in order for a sufficient condition to occur Conditional Reasoning statements have several unique features that you must know: 1. The sufficient condition does not make the necessary condition occur. Rather, it is a sign or indication that the necessary condition will occur. 2. Temporarily speaking, either condition can occur first, or the two conditions can occur at the same time. 3. The conditional relationship stated by the author does not have to reflect reality. Your job is not to figure out what sound reasonable, but rather to perfectly capture the meaning of the author’s statement Conditional reasoning occurs when a statement containing the sufficient and necessary conditions is used to draw a conclusion based on the statement. Valid and Invalid Inferences * The Repeat form simply restates the elements in the original order they appeared. This creates a valid inference. * Because the contrapositive both reverses and negates, it is a combination of a mistaken reversal and mistaken negation. Since the contrapositive is valid, it is as if two wrongs do make a right. * A mistaken Reversal switches the elements in the sufficient and necessary conditions, creating a statement that does not have to be true * A mistaken negation negates both conditions, creating a statement that does not have to be true * A mistaken Reversal of a given statement and a mistaken negation of that same statement are contrapositives of each other Two critical rules govern how conditional reasoning appears in a given sentence: 1. Either condition can appear first in the sentence. 2. A sentence can have one or two indicators In the case of “unless.” “except,” “until,” and “without,” a special two-step process called the Unless Equation is applied to the diagram: 1. Whatever term is modified by unless, except, until, or without becomes the necessary condition 2. The remaining term is negated and becomes the sufficient condition An alternate interpretation for unless and its synonyms is “if not” -When “the only” appears, be careful since physically it appears just before the sufficient condition (although the “only” still ultimately modifies the necessary condition) Class Chapter 7: Weaken Questions - Require you to select the answer choice that undermines the author’s argument as decisively as possible. - In the Third Family, requiring a different approach then Must Be True and Main Point questions Weaken Rules: 1. The stimulus will contain an argument. * Because you are asked to weaken the author’s reasoning, and reasoning requires a conclusion, an argument will always be present. * To maximize success you must identify, isolate, and assess the premises and the conclusion of the argument * Only by understanding the structure of the argument can you gain the perspective necessary to attack the author’s position 2. Focus on the conclusion. * Almost all correct Weaken answer choices impact the conclusion * The more you know about the specifics of the conclusion, the better armed you will be to differentiate between correct and incorrect answers 3. The information in the stimulus is suspect. * Typically reasoning eros present, and you must read the argument very carefully 4. Weaken questions often yield strong pre phases. * Be sure to actively consider the range of possible answers before proceeding to the answer choices 5. The answer choices are accepted as given, even if they include “new” information. * Answer choices can bring into consideration information outside of or tangential to the stimulus * Just because a fact or idea is not mentioned in the stimulus is not grounds for dismissing an answer choice * Your task: To determine which answer choice - when taken as true - best attacks the argument in the stimulus Weaken question stems typically contain the following two features: 1. The stem uses the word “weaken” or a synonym. * Words or phrases that are used to indicate that your task is to weaken the argument: ♡ Weaken ♡ Attack ♡ Undermine ♡ Refute ♡ Argue against ♡ Call into question ♡ Cast doubt ♡ Challenge ♡ Damage ♡ counter 2. The stem indicates that you should accept the answer choices as true, usually with the following phrase: * “Which one of the following, if true…” Weaken Question Stem Examples: - Which one of the following, if true, most seriously weakens the argument? - Which one of the following, if true, most undermines the argument presented above? - Which one of the following, if true, would undermine the physicists argument? - Which one of the following, if true, would most call into question the researchers hypothesis? - Which one of the following, if true, most calls into question the claim above? How to Weaken an Argument - The key to weakening an LSAT argument is to attack the conclusion - Attack is nt the same as to destroy - Instead, you are more likely to encounter an answer that hurts the argument but does not ultimately drstrou the authors position - When evaluating an ansert, sdk yourself “Would this answer choice make the author reconsider his or her position or force the author to respond?” - Because arguments are made up of premises and conclusions, you can safely assume that these are the parts you must attack in order to weaken an argument 1. The premises * One of the classic ways to attack an argument is to attack the premises on which the conclusion rests * Regrettably, this form of attack is rarely used on the LSAT * When a premise is attacked, the answer choice is easy to spot * Literally, the answer will contradict one of the premises, and most students are capable of reading an argument and identifying an answer that simply negates a premise * In practice, almost all correct LSAT Weaken question answers leave the premises untouched 2. The conclusion * The conclusion is the part of the argument that is more likely to be attacked * But the correct answer choice will not simply contradict the conclusion * Instead, the correct answer will undermine the conclusion by showing that the conclusion fails to account for some element or possibility * The correct answer often shows that the conclusion does not necessarily follow from the premises even if the premises are true Example: All my neighbors own blue cars. Therefore I own a blue car. * Although the statement that the neighbors have blue cars is completely reasonable, the weakness in the argument is that this fact has no impact on the color of the car I own. * The correct weakening answer would be something along the lines of: The cars of one’s neighbors have no determinative effect on the car any individual owns * Would that conclusively disprove that I own a blue car? No. * Does it show that I perhaps do not own a blue car? Yes. * Does it disprove my neighbors own blue cars? No. - Answers that weaken the argument’s conclusion will attack assumptions made by the author - In the ex above, the author assumes that the neighbors ownership og blue cars has an impact on the color of the car that he owns - If this assumption were shown to be questionable, the argument would be undermined - The stimuli for weaken questions contain error of assumptions - Typically, the author will fail to consider other possibilities or leave out a key piece of information - In this sense, the author assumes that these elements do not exist when he or she makes he conclusion, and if you see a gap or hole in the argument immediately consider that the correct answer might attack this hole - As you consider possible answers, always look for the one that attacks the way the author arrived at the conclusion - Do not worry about the premises and instead focus on the effect the answer has on the conclusion We know that we must first focus on the conclusion and how the author arrived at the conclusion. - The second key to weakening arguments is to personalize the argument. Common Weakening Scenarios 1. Incomplete information * The author fails to consider all of the possibilities, or relies upon evidence that is incomplete * This flaw can be attacked by bringing up new possibilities of information 2. Improper Comparison * The author attempts to compare two or more items that are essentially different 3. Overly Broad Conclusion * The author draws a conclusion that is broader or more expensive than the premises support Three Incorrect Answer Traps 1. Opposite Answers * Do the exact opposite of what is needed - in this case, they strengthen the argument as opposed to weakening it * Lure the test taker by presenting information that relates perfectly to the argument, but just in the wrong manner 2. Shell Game Answers * Occurs when an idea or concept is raised in the stimulus and then a very similar idea appears in the answer choice, but the idea is changed just enough to be incorrect but still attractive * In weaken questions, it is usually used to attack a conclusion that is similar to, but slightly different from the one presented in the stimulus 3. Out of Scope Answers * Simply miss the point of the argument and raise issues that are either not related to the argument or tangential to the argument Weakening Conditional Reasoning To weaken a conditional conclusion, attack the necessary condition by showing that the necessary condition does not need to occur in order for the sufficient condition to occur. - This can be achieved by presenting a counterexample or by presenting information that shows that the sufficient condition can occur without the necessary condition When you have conditional reasoning in the stimulus and a Weaken question, immediately look for an answer that attacks the idea that the necessary condition is required. Chapter 8: Cause and Effect Reasoning What is Causality? Cause and effect reasoning - basically asserts or denies that one thing causes another, or that one thing is caused by another - On the LSAT, cause and effect reasoning often appears in the conclusion where the author mistakenly claims that one ecent causes another Example: Last week Google announced a quarterly deficit and the stock market dropped 10 points. Thus, Google’s announcement must have caused the decline. - Like the above conclusion, many causal conclusions are flawed because there can be alternate explanations for the stated relationship - Another cause could account for the effect - A third event could have caused both stated cause and effect - The situation may in fact be reversed - The events may be related but not casually - Or the entire occurrence could be the result of chance Casuality occurs when one event is said to make another occur - The cause is the event that makes the other occur - The effect is the event that follows from the cause - By definition, the cause must occur before the effect, and the cause is the “activator” or “ignitor” in the relationship - The effect always happens at some point in time after the cause How to Recognize Basic Causality A basic cause and effect relationship has a signature characteristic: A single cause makes an event happen, - Thus, there is an identifiable type of expression that is typically used to indicate that a causal relationship is present Basic Cause & Effect Relationship Indicators Caused by Because of Responsible for Reason for Leads to Induced by Promoted by Determined by Produced by Product of Is an effect of The Difference Between Causality & Conditionality 1. The chronology of the two events can differ. a. In cause and effect statements there is an implied temporal relationship: the cause must happen first and the effect must happen at some point in time after the cause. b. In sufficient and necessary statements there is no implied temporal relationship: the sufficient condition can happen before, at the same time as, or after the necessary condition 2. The connection between the events is different. a. In cause and effect statements the events are typically related in a direct way: “She swerved to avoid hitting the dog and that caused her to hit the tree.” The cause physically makes the effect happen. b. In conditional statements the sufficient and necessary conditions are often related directly, but they do not have to be: “before the war can end, I must eat this ice cream cone.” The sufficient condition does not make the necessary condition happen, it just indicates that it must occur. 3. The language used to introduce the statements is different. a. Because of item 2, the words that introduce each type of relationship are very different. b. Causal indicators are typically active, relatively powerful words, whereas most conditional indicators do not possess those traits Causality in the Conclusion versus Causality in the Premises - Causal statements can be found in the premise or conclusion of an argument - If the causal statement is in the conclusion, then the reasoning is possibly flawed - If the causal statement is in the premise, then the argument may be flawed, but most likely not because of the causal statement - Due to this difference, one of the critical issues in determining whether flawed causal reasoning is present is identifying where in the argument the causal assertion is amde - The classic mistaken cause and effect reasoning we will refer to often in this book occurs when a causal assertion is made in the conclusion, ir the conclusion presumes a causal relationship Example of argument with a basic causal conclusion: Premise: In North America, people drink a lot of milk. Premise: There is a high frequency of cancer in North America. Conclusion: Therefore, drinking milk causes cancer. - In this case, the author takes two events that occur together and concludes that one must cause the other - This conclusion is invalid If a causal claim is made in the premises, however, then usually no causal reasoning error exists in the argument - As mentioned prior, the makers of the LSAT tend to allow premises to go unchallenged - They are more concerned with the reasoning that follies from a premise - It is considered acceptable for an author to behin his argument by stating a causal relationship and then continuing from there. Example of argument with causal relationship in the premise: Premise: Drinking milk causes cancer. Premise: The residents of North America drink a lot of milk. Conclusion: Therefore, in North America there is a igh frequency of cancer among the residents. - The second example is considered valid reasoning because the author takes a causal principle and follows it to its logical conclusion - Generally, causal reasoning occurs in a format similar to the first example, but there are LSAT problems similar to the second example Situations That Can Lead to Errors of Causality 1. One event occurs before another a. When one event occurs before another event, many people fall into the trap of assuming that the first event caused the second event. This does not have to be the case, example: Every morning the rooster crows before the sun rises. Hence, the rooster must cause the sun to rise. - The example contains a ludicrous conclusion, and shows why it is dangerous to simply assume that the first event must have caused the second event 2. Two (or more) events occur at the same time a. When two events occur simultaneously, many people assume that one event caused the other b. While one event could have caused the other, the two events could be the result of a third event c. Or the two events could simply be correlated without one causing the other d. Or be the result of random chance Third event causing both events example: The consumption of ice cream has been found to positively correlate with the murder rate. Therefore, consuming ice cream must cause one to be more likely to commit murder. - The conclusion of the example does not have to be true - The two events could simply be correlated - And the two events can be explained as the effects of a single cause: hot weather - When the weather is warmer, ice cream consumption snd the murder rate both rend to rise The Central Assumption of Basic Causal Conclusions - When we discuss causality in the real world, there is an inherit understanding that a given cause is just one possible cause of the effect, and that there are other causes that could also produce the same effect. - The speakers on the LSAT do not think typically this way when making a basic causal conclusion. - When an LSAT speaker concludes that one occurrence definitively caused another, that speaker also assumes that the stated cause is the only possible cause of the effect and that consequently the stated cause will always produce the effect. - This assumption is extreme and far-reaching, and often leads to surprising answer choices that would appear incorrect unless you understand this assumption Example: Premise: Average temperatures are higher at the equator than in any other area. Premise: Individuals living at or near the equator tend to have lower per-capita incomes than individuals elsewhere. Conclusion: Therefore, higher average temperatures cause lower per-capita comes. - This is a classic flawed causal argument wherein two premises with a basic connection (living at the equator) are used as the basis of a conclusion that one of the elements actually makes the other occur - The conclusion is flawed because it is not necessary that one of the elements must have caused the other to occur - The two could simply just be correlated in some way or the connection could be random - When an LSAT speaker makes an argument like the one above, he or she believes that the only cause is the one stated in the conclusion and that, unless stated, there are no other causesthat can create that particular effect - Thus, in every argument with a basic causal conclusion that appears on the LSAT, the speaker believes that the stated caus is in fac the only cause and all other theoretically possible causes are not, in fact, actual causes How to Attack a Basic Causal Conclusion - Whenever you identify a basic causal relationship in the conclusion of an LSAT problem, immediately prepare to either weaken or strengthen the argument Attacking a basic cause and effect relationship on Weaken questions almost always consists of performing one of the following tasks: A. Find an alternate cause for the stated effect. ★ Because the other believes there is only one cause, identifying another cause weakens the conclusion B. Show that even when the cause occurs, the effect does not occur. ★ This type of answer often appears in the form of a counterexample ★ Becuase the author believes that the cause always produces the effect, any scenario where the where the cause occurs and the effect does not will weaken the conclusion C. Show that although the effect occurs, the cause did not occur ★ This type of answer often appears in the form of a counterexample ★ Becuase the author believes that the effect is always produced by the same cause, any scenario where the effect occurred anf the cause does not will weaken the conclusion D. Show that the stated relationship is reversed. ★ Because the author believes that the cause and effect relationship is correctly stated, showing that the relationship is backwards (the claimed effect is actually the cause of the claimed cause) undermines the conclusion E. Show that a statistical problem exists with the data used to make the causal statement. ★ If the data used to make a causal statement are in error, then the validity of the causal claim is in question