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Logical Reasoning

Demon Team Feb 13, 2024Solving a Sufficient Assumption Question

Watch Nathan attack a Sufficient Assumption question from Test 73 in this comprehensive explanation. Sufficient Assumption questions are predictable. The correct answer will simply connect the evidence to the conclusion.

Demon Team Apr 1, 2022Resist the Urge to Diagram on Logical Reasoning

Why Not Diagram? One of the most commonly taught LSAT Logical Reasoning strategies is diagramming. You’ve probably seen it before—with arrows, squiggly lines, and abbreviations, Logical Reasoning diagrams can look like a boatload of gibberish. Diagramming has no place in Logical Reasoning. Consider this argument: “All elephants are pink. Dumbo is an elephant. Therefore, Dumbo is pink.” Another LSAT instructor may tell you to notate the argument as follows: E → Pink    and    Not Pink → Not E D → E   and   Not E → Not D  Therefore, D → Pink and Not Pink → Not D Maybe these notations make sense to you. Maybe they don’t. Either way, writing them down is counterproductive. It’s easier to understand the argument using common sense than to doodle it out. Given that “Dumbo is an elephant,” common sense tells us that if something is not an elephant, it can’t be Dumbo. Restating a conditional claim in this way is sometimes called identifying the “contrapositive,” but LSAT Demon teachers avoid unnecessary jargon in lessons. Diagramming takes a long time and is susceptible to mistakes. Time spent drawing arrows and rewording the same information in different ways could be better spent actually understanding the argument. Understand the Argument in Your Own Words If you get stuck on any part of an argument (in this case, if you can’t wrap your mind around the idea that all elephants are pink), try to visualize it. Don’t diagram it abstractly on paper, or you will only compound your confusion.  

Demon Team Apr 1, 2022How to Destroy Arguments on the LSAT

This article will focus on Logical Reasoning questions that involve arguments. But keep in mind that not all passages are arguments! For a refresher on what makes a passage an argument, click here. Step 0: Start with the Passage When faced with an argument in Logical Reasoning, the worst thing you can do is skim through it, passively accept its conclusion, and jump straight to the question and answer choices.  Thinking like a lawyer starts here, on your LSAT journey. LR tests your ability to push back against faulty reasoning by identifying logical flaws. Follow these next steps for the most efficient, effective method. Step 1: Accept the Premises Arguments on the LSAT may be valid and invalid. The test will throw all sorts of invalid arguments at you—with leaps in logic and conclusions that go way too far. Which claims should you object to, and which should you accept as true? Put simply, your job is to accept the argument’s premises but attack its conclusion. (If you’re shaky on the difference between premises and conclusions, read more here.) Even if a premise is false in the real world, remember that you’re operating in LSAT-land, where premises are treated as facts for the sake of argument. If, for example, an argument says, “Everyone named Benjamin is super nice,” nobody cares whether you know a Benjamin who’s a real jerk. You’re operating on a plane of logic where, for the sake of the argument, it’s a fact that all Benjamins are super nice. Accept this and move on. Trying to argue with the given facts of the argument will only waste your time. Step 2: Identify the Conclusion You’ve accepted the evidence as true. Now what? To continue the example above, let’s say the argument goes on to say, “Steve is super nice, so Steve’s middle name must be Benjamin.” This sentence contains another premise (that Steve is super nice) and a conclusion (that Steve’s middle name must be Benjamin). The alarm bells should already be ringing in your head—the conclusion isn’t justified by the facts.  Step 3: Evaluate the Conclusion You know the facts, you know the conclusion—now you decide whether the argument is valid or invalid and why. While you must accept an argument’s premises as facts, you don’t have to accept the conclusion as a fact. All arguments, by definition, have conclusions, but not all arguments prove their conclusions. Learn to spot the difference between valid and an invalid arguments. A valid argument proves its conclusion soundly, while an invalid argument does not. Anytime you hear a conclusion on the LSAT, pause to evaluate its validity. Figure out whether the author has proven what they set out to prove. Critically engage with every argument you encounter on the LSAT. Always Push Back Against Flawed Arguments Most conclusions on Logical Reasoning are unwarranted—in other words, most arguments are invalid, or flawed, in some way. Your job is to identify these flaws and argue back.  A lawyer doesn’t let the opposing counsel get away with making bad arguments in court. Likewise, you cannot allow authors to get away with making flawed arguments on the LSAT. Don’t passively accept whatever the test throws at you, no matter how reasonable or agreeable it seems. Instead, engage with it as if you were in a debate with an opponent—find the weak spots, and push back against anything that isn’t 100% proven by the premises. In the example above, the author concludes that “Steve’s middle name must be Benjamin.” But hold on a second—do the premises prove that Steve’s middle name must be Benjamin? No. The premises say that if someone’s name is Benjamin, they must be super nice. But that doesn’t mean that everyone who’s super nice must be named Benjamin. That’s the disconnect. There could be other ways to be super nice that don’t involve being named Benjamin. In other words, the author hasn’t proven that being named Benjamin is necessary for being super nice. The conclusion is unjustified. The analysis above is what it looks like to critically engage with a flawed argument. The only way to get better at identifying flawed arguments and cracking them open is to practice yourself. Start drilling Logical Reasoning questions, and watch hundreds of videos of Ben and Nathan modeling this strategy.

Demon Team Mar 6, 2022Argument Parts and Indicators

To understand LSAT Logical Reasoning questions, you must understand how an argument functions. Here’s what you need to know about arguments and how to evaluate them. Argument Basics An argument consists of one or more premises and a conclusion. A premise is a fact, or piece of evidence, that the author uses to support a conclusion. A conclusion is a claim or statement that the author supports with at least one premise. Without both these parts, all you’ve got is a claim or a set of facts. Not All Passages Are Arguments Some Logical Reasoning passages aren’t arguments at all. They may instead consist of a set of facts or principles with no conclusion. If the author isn’t trying to prove or convince you of anything, it’s not an argument. Focus on understanding the premises, and how they relate to each other.  Premises Remember: A premise is a fact, or piece of evidence, that the author uses to support a conclusion. A premise indicator is a word such as because, since, or for that often comes before a premise. In the examples below, the premise is italicized and the indicator is emboldened: 1) The world is getting warmer because atmospheric CO₂ is increasing. 2) Because atmospheric CO₂ is increasing, the world is getting warmer. In both examples, the conclusion is close to the indicator and premise. Whether the conclusion comes before or after the word “because” is just a matter of style. The order doesn’t change the fact that “because” comes right before the premise. Conclusions There are two types of conclusions: main conclusions and intermediate conclusions. Although you must accept premises as true on the LSAT, conclusions are open to debate. If an argument asserts as a premise that the world is flat, you must assume that’s true for the sake of argument—remember, you’re not being tested on your knowledge of the Earth, but your ability to reason logically. If it’s asserted as an intermediate conclusion or as the main conclusion, however, you can disagree. Main Conclusions The main conclusion is the point that the author is ultimately trying to prove. If an argument has only one conclusion, then that’s the main conclusion. If it has two or more conclusions, then the main conclusion is the one that is supported by any other conclusions in the argument. The main conclusion doesn’t have to be the last sentence; it can appear anywhere in the argument. Intermediate Conclusions An intermediate conclusion is a conclusion that supports the main conclusion. Think of it as a stepping stone on the way to the author’s main conclusion. It’s a conclusion because it’s supported by at least one premise. It also acts as a premise, because it supports the main conclusion. When a statement serves both these functions, the LSAT calls it an “intermediate conclusion.” Consider the following example: Obama is smart (premise), so he will make good book recommendations (intermediate conclusion). Therefore, you should follow him on Instagram (main conclusion). Although you have to accept Obama’s smartness as a fact, you can object to the argument in at least two ways: (1) Who says that being smart is all it takes to make good book recommendations? (2) Who says that you should follow on Instagram everyone who makes good book recommendations? It makes sense that “he will make good book recommendations” supports “you should follow him on Instagram.” It doesn’t make sense the other way around. So “he will make good book recommendations” is an intermediate conclusion. Conclusion Indicators A conclusion indicator is a word such as therefore, thus, or so that often comes before a conclusion. In these two examples, the conclusions are italicized and the indicators are emboldened: George is always late, so he’ll probably be fired. Frogs are dying all around the world. Thus, we must act now. Be wary of using indicators as a crutch for finding either the conclusion—the words therefore, thus, and so by themselves don’t necessarily introduce the main conclusion. You must look to other clues in the argument to decide what’s a premise, what’s a conclusion, and whether a conclusion is intermediate or main. Ask yourself: Is this the main, overarching point the author is trying to argue, or is the author trying to convince me of this in order to prove something else? What if There Are No Indicators? Indicators are a good starting point for understanding how arguments work. Once you get comfortable, however, you should know how to identify argument parts based solely on the information in the argument. Some difficult Logical Reasoning questions have no indicator words. Consider the following argument: Evidently, we should care about climate change; frogs keep dying everywhere. Can you figure out what the author’s conclusion is? Ask yourself: What is the author trying to convince me of? What is the author trying to sell me? In this case, the author is trying to convince you that “we should care about climate change.” The reason is that “frogs keep dying everywhere.” Once you understand how the argument functions, you can start spotting gaps in it: How do we know that frogs dying is evidence of climate change? Why should we care about frogs dying? Remember, don’t argue with the premises. Instead, attack the conclusion. Other Argument Parts Sometimes, the author will introduce information into the passage that is neither a premise nor a conclusion. These “other” parts are often background information that provide context for the argument while not contributing directly to its logic. Opinions and How to Spot Them The phrases “many scientists argue that,” “most scholars agree that,” and “it is assumed that” (and other formulations of the same idea) all introduce the opinions of other people. In most arguments on the LSAT, when the author cites an opinion of others, it’s a prelude to an argument for why that opinion is wrong in some way. In this example, the opinion is italicized:  Dr. Gingrich claims that we should create a colony on the moon. But this is a bad idea because, in this economy, we don’t have the resources to fund it. The opinion, which belongs to Dr. Gingrich, is that we should create a colony on the moon. The author disagrees with this opinion.  Test yourself: Can you spot the premise and the conclusion in the argument above? Concessions and How to Spot Them Indicators such as although, even though, and despite almost always introduce concessions. In this example, the indicator is emboldened and the concession is italicized: Although a few senators like Newt’s plan, his plan won’t be adopted by NASA. It’s already planning to go to Mars, and it doesn’t have the funding to do both. The author is conceding that some senators like the plan that the author believes will ultimately not be adopted.  Test yourself: What is/are the author’s premise(s), and what is the author’s conclusion?‍ Ready to put this advice to work? Start drilling.  

Demon Team Feb 27, 2022Valid and Invalid Arguments

What makes an argument valid or invalid? Why is validity important on Logical Reasoning? Learning the differences between good and bad arguments will improve your LSAT score. A valid argument provides all the information needed to prove its conclusion. In a valid argument, if the premises are true, the conclusion must be true as well. Examples of Valid Arguments Some valid arguments are more intuitively valid than others. Here’s a valid argument that you probably have no problem accepting: Ralph is a dog. No dogs are allowed on the roller-coaster. Therefore, Ralph is not allowed on the roller-coaster. The following argument is also 100% valid: Every dog is a reptile. Every reptile is cold-blooded. Therefore, every dog is cold-blooded. Each of the arguments above is valid because the truth of its premises guarantees the truth of its conclusion. Each conclusion has airtight support, with no room for exceptions or what-ifs. Of course, in the second example above, the premises are false in real life. That doesn’t mean it’s an invalid argument. On the LSAT, your job isn’t to argue with the premises. Your job is to accept the premises and to object when those premises don’t prove the conclusion. Listen to Demon founders Ben and Nate explain how to attack arguments here. Invalid Arguments An invalid, or flawed, argument is one whose conclusion is not proven by its premises. That is, even if all the premises are true, the conclusion could still be false. Some sort of jump in reasoning has taken place, and it’s your job to figure out where the argument went wrong. Examples of Invalid Arguments Consider the following argument: Being friendly is the easiest way to make friends quickly. Alana has a lot of friends. Therefore, Alana must be very friendly. The conclusion above is not proven by the premises. The argument tells us that being friendly is one way to make friends, but is that the only way? And does having a lot of friends necessarily mean that you are very friendly? Although Alana might be very friendly, the author hasn’t proven that she is.‍ Why is Validity Important on the LSAT? Both valid and invalid arguments appear on the LSAT. The best strategy to use on a given question depends on whether the argument you’re dealing with is valid or invalid. Figuring out whether an argument is valid is a crucial step to finding the correct answer. Identifying Arguments First, determine whether the passage is an argument. If it’s an argument, your next step is to determine whether the argument is valid or invalid. Identify the conclusion and the evidence presented in support of that conclusion. Then ask yourself: Is the conclusion proven by that evidence? Often, the author thinks they have proven their conclusion, but they actually haven’t. Don’t take the author’s word for it.‍If the argument is valid, you can’t argue with it. If it’s invalid, you must argue with it.‍ Understanding & Identifying Logical Flaws “Arguing” with the argument means pointing out its logical flaws. Maybe the conclusion is too broad to be proven by the premises. Or, the conclusion may require an unwarranted assumption. The author may have sneakily shifted their definition of a certain word halfway through the argument. Perhaps, the author tried to pass off evidence of a correlation as proof of a causal relationship.‍There are endless ways an argument can go south. On Logical Reasoning questions, your job is to figure out exactly where the author went wrong.  Start drilling arguments with our master LSAT teachers today.

Nathan Fox Jul 29, 2021Negating “Assumption Negation”

Two weeks ago, I wrote a manifesto declaring war on the “contrapositive” and all other forms of overcomplicated LSAT teacher nerd-speak. This week, I’ve got “assumption negation” in my crosshairs. (That’s right: I’m about to negate the unnecessary “assumption negation” approach to Necessary Assumption questions—say that five times fast.) I used to teach Necessary Assumption questions all wrong. I was suckered by LSAT dogma, and I thought that it was my duty to teach Necessary Assumption questions in a confusing, convoluted manner. Eventually, Ben Olson taught me how to think of them in a much simpler way. Before I get into “assumption negation” and all the wrong ways I used to think about it, let me tell you the right way to think about Necessary Assumption questions: A necessary assumption is one that the author must agree with. That’s it! The correct answer on a Necessary Assumption question is the only one that the author must agree with. It’s an awful lot like a Must Be True question. Just find the one that the author can’t possibly say no to. That’s all you have to do. Anyway, back in the old days, my NA spiel went something like this: Assumption means “missing piece,” so Necessary Assumption questions are about finding a critical missing piece of the argument that, when negated, would disprove the conclusion of the argument. The technique we use is to consider the opposite of each answer choice. If an answer can be false without it destroying the argument, then that’s not the answer. The correct answer, when false, will destroy the author’s argument. This is flat wrong in part, and even the part that might be technically correct is far more confusing than it needs to be. The part that’s dead wrong is the whole bit about how an assumption is a “missing piece” of the argument. That’s just not true on Necessary Assumption questions. On a Sufficient Assumption question, yes—you’re looking to build a bridge from the evidence to the conclusion, or from the evidence to another piece of evidence in a way that would prove the argument’s conclusion. You can memorize this: A sufficient assumption is one that makes the argument win. But Necessary Assumption questions aren’t about making the argument win at all. The correct answer frequently has nothing to do with building an affirmative case for the conclusion. And it’s not a “missing piece” in any reasonable sense of that term. Consider the following argument: Nathan wants a dog that will hike the Tahoe Rim Trail with him, his best friends, and their dog Zada. Coco, a rottweiler available nearby for adoption, has lots of energy. So Nathan should adopt Coco to hike the Tahoe Rim Trail. The correct answer to a Necessary Assumption question very well might be “Coco can walk.” Nobody in their right mind would ever say that “Coco can walk” is a “missing piece” of the argument. If it’s true that Coco can walk, it does absolutely nothing to prove that Nathan should adopt Coco. If you’re looking for a missing piece, you’re going to miss this question. But would the author of the argument have to agree that Coco can walk? Of course. Anyone recommending that I adopt Coco to hike 169 miles around the entire damn lake had better agree that Coco can walk. Duh. Another necessary assumption of the same argument would be “Coco won’t immediately and constantly attempt to murder Zada.” Again, this isn’t a “missing piece” of the argument at all. But if you’re advocating that I adopt Coco to hike the rim trail with my best friends and their dog, then of course you’d have to agree that Coco won’t immediately and constantly try to murder my best friends’ dog—otherwise, what kind of psychopath are you? The part of my spiel that, while technically correct, was confusing, time consuming, and overcomplicated was the whole bit about “negate each answer choice and look for the one that would disprove the argument.” Ain’t nobody got time for that! Adding a negative to each answer choice, then seeing if it would negate the argument, is purposely looking for a double negative. And what if the answer choice itself already contains a negative? Now we’re in triple-negative territory. Even if we can handle it, it burns up too much of our time. Instead of negating every answer, just ask, “Does this seem like something the author would have to agree with?” The correct answer on a Necessary Assumption question is allowed to be unexpected—frequently, it defends the argument against some unanticipated attack. But the wrong answers are irrelevant or extra in ways that make them obviously incorrect if you’re wearing your Must Be True hat. The correct answer is the only one that would allow you to stand up in court and say, “Yes, Your Honor, the author must agree with this statement because…” It’s true that sometimes your explanation will start with, “…you see, if the author did not agree with this statement, then their argument would make no sense.” But you really should only bother going into it after eliminating the other four answers. On your first read, just ask, “Would the author have to agree with this?” The author doesn’t necessarily have to have contemplated the issue in advance. But when confronted with it, the author would be forced to shrug and say, “Well yes, of course Coco can walk” or, “Well yes, of course I agree that Coco isn’t a dog-murderer.” When an LSAT tip sounds too complicated, it probably is. So let’s resign “assumption negation” to the ever-growing turd pile. Instead, on Necessary Assumption questions, let’s just look for the one answer that the author must agree with. (Because people will ask—no, I’m not adopting Coco. I had her for four days. As it turned out, she could definitely walk. But she also did try to immediately murder Zada every time they met. So Coco got returned to sender.) Please let us know what you think of this lesson. Email us at

Nathan Fox Jun 17, 2021You Don’t Suck at Necessary Assumption (You Might Just Suck at LR)

LSAT Demon LR/RC guru Rebecca Cumberbatch dropped this in our teacher Slack channel this week: I am noticing a real aversion to necessary assumptions recently. I think it’s a bit of mob mentality because people have seen others complaining and are drinking the Kool-Aid. Debunking the NA boogeyman might be a good newsletter article some time, @Nathan Fox When asked what she meant by “noticed an aversion,” she added: It seems like every time a necessary assumption question comes up, I get a bunch of messages in the chat like “I NEED HELP WITH NA” or “I AM SO BAD AT NA” … and these are almost always coming from people who are simply not reading slowly and carefully enough to completely understand the argument, so they can’t ID a necessary assumption when it shows up in the answer choices. I don’t think the problem is a struggle with the question type. I think it’s that the question type comes up a lot at medium/high difficulty, and they’re not understanding the argument. ($0.02) Totally. In other words, these students don’t suck at necessary assumptions. Not specifically, anyway—they might just suck at logical reasoning more broadly. Necessary Assumption questions sound like, “Which one of the following is an assumption on which the argument depends?” or, “The argument assumes which of the following?” The proper analysis on this type of question is simply, “What does the author have to agree with?” But the game is almost always won or lost before we even get to that point. The game, as always, is to attack the argument. Imagine the following argument: Nathan loves super burritos. Nathan is overweight. Super burritos are as big as your head and loaded with al pastor, cheese, carbs, sour cream, guacamole, and all manner of other calorie-dense shit that tends to make people overweight. Therefore, super burritos are the reason Nathan is overweight. This argument sounds reasonable. My love of super burritos could, indeed, be the reason I’m overweight. But if you steam ahead into the question and (God forbid) the answer choices, you’ve already failed. Your job is to disagree. Before reading the question or the answer choices, you need to find a way to disagree with the argument. Don’t argue with the premises. Accept the fact that I love super burritos. Accept the fact that I am overweight. Accept the fact that super burritos are loaded with all manner of calorie-heavy shit that has a tendency to make people overweight. Do argue with the conclusion. The game on LSAT logical reasoning is to find a way to argue with the conclusion while granting the premises as true. Is it possible that Nathan loves super burritos, super burritos make people fat, Nathan is fat, and yet super burritos are not the actual cause of Nathan’s fatness? Imagine you’re an attorney representing the super burrito lobby. Can you grant all of the evidence in this case, while still getting your client off the hook? Feel free to think creatively. Don’t get caught up in some LSAT nerd-mode panic over technicalities like “this is a Necessary Assumption question, omg I suck at these, I need to look for a necessary assumption here, so I’m looking for something the author must agree with…” Remember we haven’t even read the question yet. We’re still just attacking the argument. The game is to attack the argument. Your job is to disagree. Be creative! What if Nathan loves super burritos, but he hasn’t ever actually eaten one? Wouldn’t that get your client, the super burrito lobby, off the hook? Of course it would. So anyone trying to prove that “Nathan is fat because of super burritos” must necessarily agree with the statement, “Nathan actually eats super burritos sometimes.” What if Nathan just bought himself a whole-ass ice cream maker, of all the stupid things for a fat person to buy, and now eats about 4,000 calories of ice cream every night? Wouldn’t that get your client, the super burrito lobby, off the hook? Yep. So anyone trying to prove that “Nathan is fat because of super burritos” must necessarily agree with the statement, “Nathan isn’t fat solely because of the 4,000 calories of homemade ice cream he eats every night after stupidly buying an actual goddamned ice cream maker on Amazon.” What if Nathan is sedentary, because all he does is play Gloomhaven and Xcom, and all sedentary video game players are overweight? What if he drinks too much beer? What if he feels like Ben works out enough for both of them, and he’s trying to restore balance to the universe by never exercising and eating pizza for breakfast? All of these things are excellent weakeners. Therefore, the argument necessarily assumes the opposite of these things. The argument, “Nathan is overweight because of super burritos,” necessarily assumes each of the following: Nathan isn’t overweight because all he does is play Gloomhaven and Xcom, and all sedentary video game players are overweight. Nathan isn’t overweight because he drinks too much beer. Nathan isn’t overweight because he feels like Ben works out enough for the two of them, and he’s trying to restore the balance of the universe by never exercising and eating pizza for breakfast. The game is won or lost, regardless of question type, by attacking the argument first. Every potential attack on an argument can be turned into a necessary assumption. You need to get better at attacking the argument and phrasing objections before you even read the damn question. If you think you suck at Necessary Assumption questions, you’re probably not attacking the argument in the first place—which means you actually just suck at LR. But you can get better! I hope you’ll view this as an opportunity, not a curse. At LSAT Demon, we’re in the business of helping people learn to do the LSAT on offense instead of defense. Once you learn to do this properly, you’ll start predicting the answers all over the place—often, before you even read the questions.

Demon Team Apr 15, 2021On Logical Reasoning, Read the Passage First

If a previous instructor, website, or book told you to read the question stem first on Logical Reasoning, you can safely disregard everything else they have to say. This advice is unhelpful at best and counterproductive at worst.  Why You Shouldn’t Start with the Question Stem Sure, question types are important (learn about Logical Reasoning question types here and here). But that doesn’t mean you should read them first.  Starting with the question stem is a gimmicky would-be shortcut. Worse still, this strategy risks putting you in a weird, overly technical “LSAT mode” mindset. Forget that, and focus on attacking the argument, using common sense. If you were an attorney and opposing counsel were making some bogus claims, all your mental energy would be devoted to figuring out what’s wrong with their argument. Bring this mindset and energy to the LSAT. If you focus on understanding the passage rather than finding shortcuts, many correct answers on Logical Reasoning are predictable. Until you’ve figured out how the passage works and/or what’s wrong with it, don’t worry about the question or the answer choices. Genuine understanding of the passage must come first. There is no free lunch on the LSAT. A Topical Example To understand this process, consider the following argument: Ainsley wants to get the highest LSAT score she can. Therefore, she should read the question stem first. Without knowing what the question will ask you, take a moment to figure out (1) what the conclusion is, and (2) why that conclusion is flawed. Before reading further, stop and engage with the passage above. Done? Here are some initial reactions you might’ve had to this argument: The argument is trying to prove that Ainsley should start with the question stem. Why? Because she wants a high LSAT score. But the passage gives no evidence that reading the question stem first will facilitate Ainsley’s LSAT score improving! It also hasn’t proven that reading the question stem first is necessary for her to get her best LSAT score. Confused about what “necessary” means? Check this out.  The question might ask you to prove the conclusion with a sufficient assumption. It might ask you to describe one of the argument’s flaws. It might ask you about the argument’s conclusion. No matter what it asks, you’ll be prepared, because you’ve already taken the time to understand the passage, its structure, and its flaws. Question Types Matter Of course, it’s important to know whether you’re answering a Strengthen question or a Weaken question when you’re evaluating answer choices. But until you know what’s wrong with the argument, how can you possibly strengthen or weaken it? It’s a distracting waste of time to read the question first.  Instead, attack the argument. Then read the question to figure out which team you’re playing for. Ready to put this strategy to work? Start drilling Logical Reasoning right now. 

Demon Team Mar 31, 2021Solving “Flaw” Questions

These closed questions ask you to find the answer that describes a flaw in the given argument: Which one of the following most accurately describes a flaw in the argument? Which one of the following most accurately describes the reporter’s error in reasoning? The argument above is most vulnerable to criticism on the grounds that it… The reasoning in the argument is questionable because the argument… If you see the word except in a Flaw question, then the argument has several flaws. The wrong answers will each describe a problem with the argument. The correct answer will describe something that either doesn’t happen in the argument or isn’t a problem for the argument. Make a Strong Prediction Ideally, you’ll have already pinpointed at least one problem after carefully reading the argument. But if not, take a moment to find one. Here’s how: Find the main conclusion. (If you have trouble, refresh your memory on argument parts and indicators.) ‍Find the premises. Don’t assume that all the statements other than the main conclusion are premises. The passage might include an opposing viewpoint, some background information, or a concession.‍ Figure out why the premises don’t prove the main conclusion. Even when you accept the premises as true, the flaw prevents the conclusion from being proven. Focus on exactly what the argument is saying to avoid subconsciously helping it. Don’t make the very assumptions that the test writers are trying to hide. Many arguments have more than one problem. After you spot one or two, describe them in your own words. Then, head into the answers. Eliminate Wrong Answer Choices Weed out incorrect answer choices by asking yourself these two questions: Does this answer describe something that the argument actually does? If not, it’s not the correct answer. Move on. If it does match something in the argument, proceed to question. Does this answer describe a problem for this particular argument? If not—if the answer choice doesn’t pose a problem for the conclusion—it cant be the correct answer. Breaking Down Answer Choices As a rule of thumb throughout the LSAT, if a sentence sounds wordy, long, or confusing, then break it into parts - the underlying idea is usually simple. On Flaw questions, answer choices often sound abstract. When you read them part by part, ask yourself whether that part accurately describes something that happens in the argument. Consider this question and one possible answer: The professor’s reasoning is flawed in that her argument… (A) treats a condition that by itself is sufficient to make an action wrong as though it were necessary for that action being wrong. In your mind, break this answer into two parts: The argument takes a condition that by itself is sufficient to make an action wrong. The argument treats that condition as necessary in order for the action to be wrong.  (Need a refresher on the difference between sufficient and necessary? Check out this video.) First, restate part 1 in your own words. It says that there’s a sufficient condition in the lawyer’s argument for something being wrong. Ask yourself: “Does the passage contain a sufficient condition that makes an action wrong?” If not, move on to the next answer choice. But if so, keep reading, because it could be the right answer. Part 2, in simple terms, says that the argument takes part 1 to be necessary. Since the question assumes that “the reasoning in the lawyer’s argument is flawed,” the author is saying that the lawyer is treating a condition as though it’s necessary when it’s actually sufficient. Ask yourself: “Does the lawyer in the passage treat the sufficient condition from part 1 as if it were necessary?” If so, keep reading this answer choice.  You’ve established that the answer choice is describing something that the lawyer actually does. Next, ask yourself:  Is this a problem? If you fixed this flaw, would it significantly help the lawyer’s argument? If so, this is probably the correct answer choice.  The correct answer will accurately describe something that’s happening and will be a flaw or problem with the argument. If the answer is “no” to any of the questions above, you can stop and move on—that answer is wrong. The Two Most Common Flaws Make sure to familiarize yourself with the flaws below—they’re sure to come up on every test you take.  Confusing sufficient with necessary Confusing correlation for causation Watch Ben discuss these flaws in more depth here. Test Your Understanding! Match the following arguments to the criticisms to which they’re most vulnerable. These are examples of some of the most common flaws that appear on the LSAT.  Arguments:  “Every word in the Bible is true because it says so in the Bible.” “A study rewarded certain kindergarteners for their good behavior with 10 minutes extra playtime at recess. Some teachers objected, feeling that schools have a moral obligation to give students as much educational time as possible while they are at school. Still, at the end of the school year, the results of the study showed that the children selected for the extra playtime far outperformed the other students in their ability to read. Therefore, if we want to enhance our students’ ability to read, we should reward them with extra playtime.” “Herbert is a nutjob who routinely mixes up his lefts and rights. Therefore his tax plan is bad for the country.” “Today I splurged and bought a dozen expensive ingredients for a gourmet recipe I have long been planning to make. For every single ingredient in the dish, I bought the finest gourmet product available. Therefore when I prepare this recipe tonight using these ingredients, it is sure to be a gourmet dish.” “Evolutionists think that a fish was swimming along and one day a leg popped out the side, and another leg popped out the other side, and the fish started walking along the beach. This could never have happened, therefore the theory of evolution is wrong.” “Being run over at a football game tailgate party by a U-Haul full of kegs of beer will kill you. John died this weekend, therefore John must have gotten run over by a U-Haul full of kegs of beer.” “Last night I went out to dinner at a fine restaurant. I had the most expensive dish on the menu. It was delicious. The restaurant was so expensive that I spent my week’s paycheck on the meal. It is clear to me that each ingredient of the dish must have been extremely expensive to procure.” “People with dogs spend a lot of time walking. Therefore a propensity to walk causes one to own a dog.”   Criticisms: A) Infers, from the fact that a certain condition is necessary for another condition to exist, that the first condition must be sufficient to prove that the second condition exists.  B) Infers causation, where only correlation has been shown.  C) Assumes what it purports to show is true.  D) Assumes that if all parts of a whole have a certain characteristic, then the whole must have that same characteristic.  E) Assumes that if a whole has a certain characteristic, then each part of the whole must have that same characteristic.  F) Criticizes the proponent of a policy rather than the policy itself.  G) Proposes a distorted version of an opposing viewpoint, in order to more easily attack that viewpoint.  H) Relies on a sample there is reason to believe is biased. Answers: C H‍ F D G A E B

Demon Team Mar 31, 2021Solving “Role” Questions

These closed questions ask you to describe what one of the claims in the argument is doing: The claim that there is a crisis in journalism plays which one of the following roles in the critic’s argument? The statement that storms are dangerous serves which one of the following functions in the argument? The claim that people sleep better after exercise figures in the argument in which one of the following ways? Make a Strong Prediction Role questions are perfect for making predictions. All the information you need is in the passage, and there’s zero guesswork. Logical Reasoning experts can predict the correct answer to Role questions every single time.  Although the passage has to be an argument, it doesn’t have to be flawed.  Before you read the answers, make your prediction: Find the main conclusion. You should have done this before even reading the question. If you’re still having trouble, brush up your skills on spotting conclusions or go back to the basics of argument parts and indicators. Find the specific claim mentioned in the question. For example, let’s say the question asks: “The statement that drinking coffee in the morning is correlated with increased levels of anxiety plays which one of the following roles in the argument?” Figure out where the passage discusses a morning coffee’s relationship with anxiety levels. Describe the role of that claim in your own words. Is it the main conclusion? An intermediate conclusion? A premise? A concession? An opposing viewpoint? Something else entirely?  If the claim is the main conclusion, you’re done. If it’s something else, figure out how it relates to the main conclusion.  If the claim helps the main conclusion, it’s likely either a premise or an intermediate conclusion.  If the claim hurts the main conclusion, it’s probably a concession or an opposing viewpoint.  Once you’ve made a strong prediction, look for the answer choice that matches it. What to Look For  The correct answer must describe exactly what’s happening in the argument. If the claim you found is the main conclusion, for example, but the argument also has an intermediate conclusion, then saying it is “the author’s only conclusion” would be wrong since it’s not the only conclusion in the argument. And if you’ve made a good prediction, the answer choice should match your prediction. Break down the answers and read them part by part. Ask yourself if each part accurately describes something that’s happening in the argument. Replace the answer choice’s abstract words with concrete ideas from the passage. Consider this possible answer: A)  It is a premise that, in conjunction with another premise, is intended to support the argument’s conclusion. You can break this answer into three parts:  a premise that in conjunction with another premise  is intended to support the argument’s conclusion After reading part 1, ask yourself, “Is the statement describing a premise?” If so, keep reading. After part 2, ask: “Is the statement working with another premise?” If so, read part 3 and restate it, asking: “Do these statements together try to support the main conclusion?”  If the answer to any of these questions is “no,” stop reading. It’s not the correct answer. Move on to the next answer choice.


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