Student Question

Why the written explanation for (B) say “the restoration helped make it clear to art historians that the original colors were different, not that the restoration changed the colors.” The stimulus says "Art historians are now acutely aware that the colors of the works they study may differ from the works’ original colors." Does this mean the restoration/cleaning damaged the original work, or does it mean that it helped it reveal the true original work? It seems like it could be either way.

Tutor Answer

I completely empathize with the feeling that "it could go either way." I had the same reaction when I first read the stimulus. But a key point is made in the last sentence. We are told the following:

"Art historians have concluded from this that interpretations of the frescoes that seemed appropriate before the frescoes' restoration may no longer be appropriate."

The word "before" is key. By using "before," the author is telling us that the restorations revealed something about the paintings which was previously unknown. Pre-restoration interpretations were flawed. Post-restoration interpretations are more accurate - i.e., they better reflect the true original work. It's just this point which the author is making when they say: "Art historians are now acutely aware that the colors of the works they study may differ from the works’ original colors."

Student Question

Can we assume that photons and neutrinos are emitted from the supernova simultaneously?

Tutor Answer

t's a great question. Context is key. We are told that the photons and neutrinos in question were emitted by a supernova. As defined by the stimulus, a supernova is the explosion of a star. Implied is an event which occurrs suddenly. Since the photons and neutrinos were emitted in a supernova event, it's likely they were emitted simultaneously.

The assumption you mention, in other words, is reasonable. Can it be proved? That's a hard question to answer. I would argue that the assumption is heavily implied. But technically speaking, a supernova may not necessarily lead to "simultaneous" emissions of photons and neutrinos.

But our goal is not definitive proof. This is not a sufficient assumption question. Our goal is only to strengthen the argument. At minimum, the scenario outlined in the stimulus likely encompasses the same scenario described by AC B. That is more than enough to make the argument more likely to be true. AC B, in other words, successfully strengthens the argument.

Student Question

Why should I not take the statement that “if she had gotten an A on her term paper, she could pass the course even without doing the class presentation” as a true statement? I thought we should believe everything in the stimulus to be true?

Tutor Answer

The statement you cite is indeed true, in so far as all premises on the LSAT should be interpreted as factual. However, that statement does not preclude answer choice (AC) A from being true.

It might help if we translate: "if she had gotten an A on her term paper, she could pass the course even without doing the class presentation." In effect, we are being told the following:

A on term paper (A) --> pass w/o presentation (B)

Condition A is sufficient for condition B. But it is not necessary. One cannot simply negate "A" in order to negate "B."

An example might be instructive. We know that an A on the term paper is sufficient for Joan to avoid the presentation. But is a B also sufficient? Possibly even a C? We don't know the answers to those questions. All we know is that an A leads to "pass w/o presentation." Other conditions might also lead to that condition as well.

The author, however, has taken a sufficient condition to be a necessary condition. An assumption is being made that an "A" is the only grade which leads to "pass w/o presentation." We don't know if that is true. It's for this reason AC B is correct.

Student Question

The passage says “Defying the external forces of racism and bureaucracy, and overcoming internal artistic and personal differences, the people working in these units arguably came closer than any other group of African American theater artists had come before to founding a truly national black theater” – doesn’t this imply that the Harlem Renaissance artists were more polarized (less amenable to agreement) than the people in the units [one of the wrong answers is B, which says this]?

And also, “philosophical and aesthetic disagreements” [right answer, C] strikes me as disagreements over what beauty is (aesthetics) and like Kant or other philosophers, not “some producers favored folk dramas exploring rural roots and culture; others preferred urban realistic dramas depicting contemporary dilemmas for African Americans; and still others advocated adapting dramas written by white playwrights for performance by African American acting troupes,” which seems less abstract/philosophical.

Tutor Answer

It's a great question you ask. The essence of your question revolves around the following: Does "overcoming internal artistic and personal differences" in order to found the first "truly national black theater" imply that negro units were relatively less polarized? In answering that question, it's important to note that overcomingissues of polarization does not imply that a group is less polarized. Other incentives may have existed which outweighed issues of polarization - federal funding and support are two possible factors.

Context helps push us towards an "overcoming" interpretation. At the beginning of P2 we learn: "the question of what kinds of plays the Negro Units should produce gave rise to vigorous, sometimes heated, debates." The Negro Units themselves experienced intense disagreement. Moreover, those disagreements "resulted in a wide range of productions reflecting the diverse views and interests of the African American community." Together, both sentences imply that a high level of diversity and conflict existed within the Negro Units. Far from being less polarized, the Negro Units may have simply been a microcosm of the larger artistic disagreements spread throughout the African American community.

In either case, it's important to note that the passage never describes the level of polarization among artists of the Harlem Renaissance. That topic is simply not discussed, and thus we can't say how "polarization" may have compared between the two groups of artists. On that basis alone, we can eliminate AC B.

AC C: It's important to note that the question stem frames the question as "most likely to agree." The correct AC does not have to be 100% true per se - some wiggle room exists. These questions do not function like a MBT on LR.

Let's hone in on the middle of P2:

These debates were motivated in part by larger debates over whether black theater should attempt to blend into mainstream culture or capitalize on its difference from the cultural mainstream; whether it should aim for the African American or the white part of its audience; and whether it should endeavor to instruct or be content simply to entertain.

In other words, the debates which occurred within the Negro Units revolved around the purpose of the play's themselves: what role should they serve? how should they be perceived? These are philosophically oriented questions oriented on the purpose and nature of a specific art form.

We also know that the disagreements cited above led to a "wide range of productions reflecting the diverse views and interests of the African American community." The statement "diverse views and interests" is broad enough to capture questions of philosophy and aesthetics. That sentence, combined with the discussion above, is enough to make AC C supported.

Student Question

Here, would AC (E) be the correct answer if we were only looking at “The percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision, so intensive supervision is no more effective”? Whereas (C) touches on the specificity “in preventing criminals from committing additional crimes”, by saying they didn’t commit extra crimes? I really struggled with this one.

Tutor Answer

First off, I just want to say that I completely empathize with how you feel. This is a very difficult question.

Let's start with answer choice (AC) E. The AC focuses on absolute numbers, not percentages. The stimulus, however, only focused on the latter. Specifically, we were told that "the percentage of released criminals arrested while under supervision is the same for intensive supervision as for routine supervision." Equivalent percentages leave space for differences in total numbers, as is the case in AC E. The AC does not need to be assumed.

AC C hones in on a subtlety that is easy to overlook (I know I did). The stimulus told us that the "percentage of released criminals arrested" was the same between both groups. The conclusion, however, makes a statement on crime. Arrests do not necessarily correlate to total crimes committed. Certain crimes may go unreported. Criminals might not be caught. In either case, the number of people arrested may not correlate to the actual number of crimes committed.

It may help to negate AC C: "The proportion of arrests to crimes committed WAS significantly higher for criminals under intensive supervision than for those under routine supervision." In other words, the crimes committed by criminals under intensive supervision more closely matched their arrest rate then was the case for those under regular supervision. The latter committed more crimes - they just weren’t arrested as frequently. If true, the argument falls apart: it would no longer be the case that "intensive supervision is no more effective."

AC C cannot be negated, because doing so collapses the argument. In other words, the argument requires AC C to be true - it is a necessary assumption of the argument. It's for this reason AC C is correct.

Student Question

I'm confused with (A). When the passage said "freudianism, for example, ..." , I thought it was explaining the sentence before it, which is about freudiansim being considered a grand theory. So, I naturally thought (A) was correct. The sentence "freudianism, for example, ..." also does relate to the idea about unversality.

Tutor Answer

The crux of question 26 comes down to the following difference: What were the notable elements of Freudianism vs. what made Freudianism a "grand theory." Answer choice A is focused on the former; question 26 is asking us to focus on the latter.

It might help to look at this from a different perspective, via the following question: Are grand theories those which view "psychological traits as universal rather than particular to the individual" OR those which "attempt to account for a broad range of historical phenomena with a single, ambitious explanation"? Grand theories are the latter. Viewing psychological traits as "universal" is not sufficient to make something a grand theory. For a theory to be "grand," it must also then say that those "universal traits" explain a "broad range of historical phenomena." AC A is missing that component - i.e. it does not touch on how universal psychological traits explain a "broad range of historical phenomena." It's for this reason that AC A is incorrect.

Student Question

I’m not fully satisfied with the explanation of why AC D is incorrect. If AC D had said “Among office workers who NEVER use keyboards...” then I feel like I understand it's comparing two unlike groups (office workers who type similar amounts and those who don’t type) and therefore irrelevant. But the stimulus says “similar amounts of typing”. I understand I could assume that since we are talking about repetitive motions that it is kinda implied that the repetitive motion is typing and not something else. But couldn’t person A who rarely uses a keyboard and person B who rarely uses a keyboard in fact be workers who do similar amounts of typing and therefore would be a relevant example of whether or not the control over their work contribute to carpal tunnel?

Tutor Answer

Answer choice (AC) D is very tricky. As you mention, the group described in AC D could be people do similar amoutns of typing. That's definitely possible. And if true, AC D would match the stimulus.

Let's assume that AC D is indeed one and the same as the stimulus - i.e., two groups of people who do similar amounts of typing, but one experiences higher rates of carpal tunnel syndrome. Does that help us answer question 15?

The question stem asked us to find something which helps "explain the study's findings." To accomplish that task, we must find an AC which offer new information - something not previously known, and which helps us understand why the paradox exists.

AC D does not provide anything new. The only effect of AC D is to provide another example of the samephenomenon. We remain unable to answer the underlying question - why does a discrepancy exist between those with the "least control" and those with the "most control?" AC D does not help us answer that question. It's for this reason that AC D is incorrect.

Student Question

So I was in between A and C. I did not think that B, D, or E applied to the scenario. I thought that C was right because technically the goal of the scientists was to reverse the harmful effects, but now the environmentalists are upset because they are trying to prevent ANY pollution? A: I do agree that they two cases are different in a critical aspect because the experiment was crucial to the ultimate cause of reversing damage to the ozone layer.

Tutor Answer

Answer choice (AC) C is very tricky. It's close to being descriptively accurate, which makes it seem relevant. But is it relevant? The environmentalists have specifically compared the space craft to an average factory. Since the latter produces an unjustifiable amount of pollution, then so must the former.

The word "unjustifiable" is key. What makes something unjustified? That question can only be answered in regards to an "average factory." The environmentalists explicitly labeled that kind of pollution as unjustified. But that doesn't mean that one can infer something else, simply because it produces the same level of pollution, is also unjustified. In order to make that inference, one must show that the "something else" is nearly one and the same as the thing which has been labled unjustified. Anything less constitutes an unfounded inference.

The environmentalists have made an unsupported inference. Two cases which differn in reportant respects have been treated as one and the same. Since one is unjustified, the argument goes, so must be the other. But the other is not nearly similar, and thus the argument fails. The environmentalists, in other words, have made an apples to oranges comparison.

AC C fails to capture that underlying flaw. It might be descriptively accurate, but it doesn't represent a flaw in the argument. It's for this reason AC C is incorrect.

Student Question

I was a bit confused by the correct AC. I thought that when the author mentions a solution to a problem, that is always included in the MP summary. In this passage, at the end, the author says “it is important to work toward identifying the additional factors that determine whether group cohesiveness will deteriorate into groupthink...”. Isn’t that the author giving advice on how to mitigate the problem? I read that and alarm bells went off in my head that that statement needed to be included in any MP summary I made, but the correct AC doesn’t include the author’s suggested solution at all.

Tutor Answer

The MP can sometimes encompass the author's proposed solution to a problem. But not always. Did the author set out to solve a problem? That question is critical. If the purpose of the passage was not to propose a solution, then the MP likely is not that solution. In other words, simply mentioning that a solution to a problem exists does not automatically trigger the MP.

The author's MP encompasses the idea that "high cohesion groups" have potential downsides. What are those downsides? The phenomenon of groupthink. The author spends the first two paragraphs describing the theoretical underpinning of low and high group cohesion, with particular focus on the latter and its connection to groupthink. Paragraph 3 moves the discussion from the abstract to the specific: we learn about the various factors which can lead to groupthink. Does high cohesion necessarily create those factors, and thus cause groupthink? Not necessarily. High cohesion is involved in the process, but it is not sufficient to create the phenomenon itself. Something else might also be required.

The last point is the meaning of the "solution" identified in the last sentence. It plays a qualifying role. We are being told that "high cohesion" only goes so far in explaining the phenomenon of groupthink. But simply because it qualifies the author's claim doesn't make it the claim itself. The MP remains the MP, albeit limited in scope by the information provided in the last paragraph.

Student Question

I’m still confused on why D is incorrect. I felt with this question while E could be the flaw, since the argument was focused on the current methods the company is us using that E was then incorrect, or at least out of scope since it was bringing up new information by saying the argument “ignores the possibility there currently better options.” Like I was thinking, ok but were focused on the methods they’re currently using not other ones they’re not using which is what then led me to go with D. I also felt the confusion “We have been falsely criticized for not being an environmentally responsible corporation” fell in line with answer D because it overlooks the fact that decreasing the amount of pollution doesn’t mean they have succeeded at being as evionremntally responsible as they could be.

Tutor Anaswer

You're correct in noting the CEO's focus on the company's current methods. But it is also true that the corporation's current methods are being compared to another option - those methods which would not produce any pollution. The latter, as the CEO explains, do not currently exist. And since they don't exist, the company must be doing "all they can to pollute less."

The CEO's conclusion does not follow. Why? Because a false dichotomy has been constructed between the company's "current methods" and those methods which would completely eliminate pollution. Eliminating the latter does not make the former the only other option - other options might exist. There may be a third option between those two. It might be possible, for example, to eliminate up to 99% of pollution.

The CEO has ignored those possibilities. In doing so, the CEO is able to conclude that the corporation is doing "all they can to pollute less." This is flawed reasoning, since it's possible that more could in fact be done to reduce pollution. Only AC E properly captures that flaw.

Student Question

I am not sure why this E is incorrect still. I think for me the jump from overall writing to fictional writing threw me off so I tried to look for an answer that bridged the connection between fictional writing specifically and immoral characters/attractive qualities. Could you please further explain why in this case we didn’t need to pay attention to the “fictional” aspect of it and why E would be wrong?

Tutor Answer

Context is key. In the first sentence, the literary critic discusses the attribution of "attractive qualities to immoral characters..." The word "attribution" is important: writers are deciding how a character is perceived and what traits they will possess. That kind of writing is not possible in non-fiction. Real people and events are being described. Some wiggle room is possible in the style of writing utilized by the writer, but the qualities of the people being described can't be changed. It's also unlikely that the word "characters" would be used if the literary critic did not intend to mean "fictional" writing.

But let's assume the author did intend to mean "all writing" in the first sentence. And let's also assume that the conclusion only focused on fictional writing - the "unrealistic" aspect is no longer important. In other words, we are only trying to connect "writing" to "fiction." Even in that scenario, AC E still fails. No connection is being established between "writing" and "fiction."

It might help to reword AC E: "it's hard to know if a fictional quality is meant to be good or bad." That something is "hard to know" doesn't help us understand why "writing" and "fiction" are disconnected - it is irrelevant to that question.

It's also irrelevant to the real gap in the argument: refraining from attributing attractive qualities to immoral characters and unrealistic. We need to know why "refraining" necessarily makes something unrealistic. AC E is not relevant to that question. It's for that reason AC E is incorrect.

Student Question

I had some trouble choosing between A and B for this question. While reading the argument, I recognized that the author was criticizing the proponents of the argument, so I initially thought A was correct. However, I read choice B and ultimately ended up choosing it, because it seemed to me that B was more closely attacking the conclusion than A. I may be overthinking here, but I thought that since passage said that the “criticism should not be taken too seriously,” the conclusion wasn’t that the criticism was wrong per se, but rather that the criticism was insincere. After all, an insincere argument can still be correct. That made answer choice B more appealing, since it’s attacking the sincerity of the criticism rather than the criticism itself. Could you help me figure out if my thinking is totally off-base here, or if there’s something about the argument and/or either answer choice A or B?

Tutor Answer

When I see a phrase like "they should not be taken too seriously," I immediately think along the lines of "that person shouldn't be believed" or "that person is probably wrong." Why? Let's say that person A tells me the earth is flat. Person B tells me that person A's claim shouldn't be taken too seriously. If that claim shouldn’t be taken seriously, then it probably shouldn't be believed. Something which isn't serious is akin to something which isn't supported.

The author means to say "the criticism is wrong." That is the meaning of their statement. If the author had meant to say "insincere," the language utilized in the stimulus would have been more explicit - something along the lines of "that person doesn't really believe what they say." The stimulus is missing that kind of language.

Student Question

I’m confused on how this is the right answer and not a response that would prove the virus being “not harmful” as a weakening to the argument? I am unsure how the farmers being able to control effects of the virus are more weak to the argument than simply just saying that the virus was caused bye other things

Tutor Answer

Let’s quickly review the argument. We are told that "[clearly], CXC has increase in virulence" during the past five years. Why? Because the death rate five years ago was 5%, and yet today it is 18%. The higher percentage indicates a more virulent disease, hence the aforementioned conclusion.

Except something has been left unconsidered. What if the numbers are not representative of the total population? What if, for whatever reason, farmers are only reporting the more serious cases of CXC? If true, then the virulence would only appear to be higher.

The "whatever reason" is provided in answer choice (AC) D. Since farmers have learned how to better treat "mild" cases of CXC, they now only report more serious cases of the disease to vets or other authorities. And if they are only reporting non-mild cases (i.e., more serious), then the number of deaths would likely appear higher. Authorities are only "seeing" the cases which are reported, not realizing that those cases are in fact unrepresentative of the total population.

The conclusion, in other words, is now less likely to be true. The percent change may simply be the result of different reporting practices, not an increase in CXC virulence.

Note that this alternative possibility was not considered by the argument. It was a gap which the author simply assumed did not exist. AC D show's that assumption may not actually be true - it is, in other words, exploiting that aforementioned gap. Almost all weakening questions will operate in this manner: an argument will be made, but something important will be left unaddressed, and thus a gap exists. Alternative explanations fit in the space left open by that gap. The correct AC will be one of those possible alternative explanations.

Student Question

AC (C) was tempting because of the lines "it is ironic, then, that the Movement fostered an ideology of design that proved to be at odds with the way buildings were really built." Doesn't this line suggest that the passage was trying to correct the misunderstanding that the proponents of the Modern Movement had?

Tutor Answer

The emphasis in AC C on "correcting a misunderstanding" implies that a current misunderstanding exists. We don't know if that is or is not true. There may be current proponents, or there may be not. In either case, the author does is not addressing current proponents of the movement. The passage is mostly written in the past tense - words like "was," "recognized," "occurred" all indicate that the author is analyzing past events. Moreover, the author never transitions to a discussion of current modernist proponents.

It's important to note that one cannot retroactively correct past mis-understandings. Proponents of modernist architecture made mistakes - those mistakes can't be changed. The modern movement declined and is now less popular. Why did that happen? Because the modern movement architects failed to abandon their counterproductive ideals. Answering that question is the primary purpose of the passage. Only AC A properly captures that dynamic.

Student Question

“She argued that the prevailing political inequality kept women at a disadvantage in all their dealings with men, including marriage, and that this ubiquitous disadvantage would continue until women were granted full political rights, equal access to property, and public employment.” This seemed to prove C for me, as it implies that marriage is an ‘ubiquitous disadvantage’ (so it’s ‘inherently unequal’ as worded in C), and it will be that way UNLESS women are granted ‘equal access to property’ (so, using conditional logic, IF property isn’t ‘equally shared,’ THEN marriage will stay ‘unequal,’ as worded in C). Does this not prove C? I get that D is also implied in the passage, but C seems to have even more concrete backing.

Tutor Answer

The issue with AC C is the focus on "property." We don't know if that terms necessarily means the same thing as "political power." The latter is the focus of Gouge's strategy, not the former. Political power might indeed lead to equal property, and thus marriage equality. But the problem remains: without political power, the inequality experienced by women will continue to be perpetuated.

It's important to look back at the question stem. The focus is on whyGouges would have likely believed that the attainment of marriage equality is insufficient for achieving overall equality. The "why" is the crucial aspect. It is another way of asking for her underlying reasoning. What is that reasoning? The idea that “political inequality is the source of women's unequal position in society.” Political power is not one and the same as property ownership. By focusing on the latter, AC C missed the underlying reasoning employed in Gouge’s argument. It's for this reason AC C is incorrect.

Student Question

I’m confused how JY landed at /fertiliser means /vulnerable, /pesticides, and healthy. Isn’t that making a sufficient-necessity error? The passage states that if fertiliser is applied, then it vulnerable, pesticides and /healthy. But A→B does not mean /A→/B, right? Just /B→/A. The vegetables could be vulnerable, have pesticides and be unhealthy in other ways.

Tutor Answer

Technically you are correct. As you mention above, one cannot simply add "/" to a conditional statement without also fully reversing that same statement. Taking the contrapositive, in other words. That rule applies only for strictly conditional statements.

J.Y. is not trying to represent the contrapositive of "fertilized. "He is instead representing two separateconditional statements. In the stimulus, those statements are written as a comparison: vegetables grown in fertilized soil vs. non-fertilized soil. Only the former is explained in detail (i.e., fertilization leads to pest vulnerability, which leads to pesticide use, which ultimately leads to health risk.) But through inference we can also discern the latter. Why? The phrase "all things being equal" tells us that one statement is more of another, and vice versa. In other words, "fertilized" leads to certain conditions when compared to "not fertilized." It's that dynamic - the relative differences between both conditions - which J.Y. represents in the video.

Student Question

So for E, how are we concluding it is the right answer? Are we saying that since mate is more widely used in Paraguay than anywhere else, it's been in use there longer than anywhere else and thus originated from there? When we encounter "the more/less x, the more/less y" statements like these, can we "swap" the former and latter sentences like that?

Tutor Answer

You're close, but one important piece is missing. Let's look back at the argument. All we know is that maté is used "more widely in Paraguay than anywhere else" and that more varieties of maté can be "found in Paraguay than anywhere else." Those premises seem to be leading to the following conclusion: maté is more popular in Paraguay than anywhere else. And yet, the argument concludes that maté "originated" in Paraguay. How? Nothing in the stimulus discussed any kind of connection between popularity and origin. The question remains unanswered.

AC E helps answer that question. In effect, it provides us with an additional premise. We learn that a potential causal relationship exists: the longer x has been in use at a certain location, the more widely x is used at that same location. The former may cause the latter.

Let's apply the above to what we know from the stimulus. maté is used more widely in Paraguay than anywhere else. AC E helps explain why that is the case: the longer a beverage has been used, the more widely that beverage is used. If the latter is used more widely than anywhere else, than it may be the case that it also has been in use longer than anywhere else.

Note the word "may." That word is highly intentional. AC E is not proving that maté has been used in Paraguay longer than anywhere else. It's possible that something else is causing the wide use of maté. We don't know with certainty that "duration" is the cause. But even so, AC E at least tells us that it could be a cause. This is more than we knew before: prior to AC E, no connection existed between "widely used" and duration of use. Now we know that one could exist, even if it doesn't necessarily exist.

We can't simply swap the former for the latter sentences, as you mentioned above. But we don't need to do so in order for AC E to be correct. AC E merely needs to establish that duration of use might cause something to become widely used. Or in other words, that a connection could exist between those two elements. AC E accomplishes that task. In doing so, it makes the conclusion more likely to be true, even if ever so slightly. It's for this reason AC E is correct.

Student Question

Can I get a better explanation of why C is incorrect? My thought process was that i know that legal positivists believe in consensus, is that at odds with moral intuition? In my low-res summary for P2, I wrote “legal positivist = morality vs law... consensus>”. Is c) Incorrect because legal positivism does not rely on logic, but more so on agreement (consensus). If so how does that make D) right?

Tutor Answer

Your analysis is spot on. Legal positivism relies on consensus, not the internal logic of the law. Dworkin proposes the latter as an improvement to the former.

The role of consensus in legal positivism does not preclude answer choice (AC) D from being the correct answer. In effect, AC D describes a requirement for consensus. Jurists need to first form an interpretation of the law's meaning. Only then can a consensus form. In other words, consensus itself derives from individual "interpretations." Because if not, why would a consensus even need to be found in the first place? The fact that legal positivism requires consensus implies that jurists, each with many possible different opinions, must agree on one common interpretation.

Student Question

Regarding this question, I am a bit confused about how to diagram it. I’m also wondering why the word “only” is treated as a biconditional

Tutor Answer

The word "only," in a vacuum, doesn't trigger a biconditional. In the context of this stimulus, however, it does have that effect. Why? Because of the way in which it interacts with the phrase "brought about."

Let's say we have a scenario where X is brought about by Y. If X is brought aboutby Y, then Y must be sufficient for X - the former "brings about" the latter.

Let's now add in "only." If X is brought about only by Y, then suddenly Y is also necessary for X. Why? Because "only" triggers a necessary condition. Y is now both sufficient (i.e., brings about) for X, and necessary.

The same dynamic is at play in the stimulus. If a "political structure (PS) is brought about only by certain ecological or climatic factors (E-CF)," then the latter is both necessary and sufficient for the former. The PS is caused by certain E-CFs, and yet simultaneously must have those same E-CFs. Both exist in a biconditional relationship.

Let's expand the aperture to the larger diagram. (PS <--> E-CF) is only the sufficient condition. The necessary condition can be translated to the following:

NO similarly structured societies not subject to those factors = /(PS and /E-CF)

NO societies that, though subject to those factors, are not so structured. = /(E-CF and /PS)

Combined = /(PS and /E-CF) and /(E-CF and /PS)

When combined with the sufficient condition, we get the following statement: To be sure a (PS <--> E/CF) --> then /(PS and not caused by E/CF) and /(E/CF but not PS).

Student Question

Can you explain why AC C stregthens the argument?

Tutor Answer

AC C strengthens the argument because it precludes an alternative possibility. The argument overlooked the possibility that all hepadnaviral fragments insert into the same portion of any animals’ chromosome. In other words, the author assumed the hepadnaviral fragment process is random. And if random, then it can't be coincidental that both the zebra finch and dark-eyed junco just happen to have fragments located in the exact same position.

As we learn in the stimulus, hepadnaviral fragments pass down to all of an animal's descendants. Given that both the zebra finch and dark-eyed junco have fragments in the same location, then the fragment itself must derive from a common ancestor. Both birds diverged at least 25 million years ago, which means the virus fragment must be at least that age or older.

Except what if the process isn't random? What if all infections lead to virus fragments in the exact same location? If true, then the same "precise" location of fragments in both the zebra finch and dark-eyed junco would not be compelling. In fact, it would be expected- any infection would necessarily lead to the two birds having virus fragments in the exact same location. This possibility dramatically undermines the author's argument. We would have less reason, if any, to believe that shared virus fragment locations equate to common ancestral infections.

AC C eliminates the above possibility. We now know that virus insertion does indeed occur randomly. And if random, then it would be profoundly coincidental for both birds to share a common fragment location. Common ancestral infections are likely at play.

On strengthening questions, always be on the lookout for damaging alternative possibilities - the kind that serve as potential sources of weakens. Correct ACs "wall off" those possibilities.

Student Question

Is Answer choice A not a restatement of the premise, how is it an alternate cause?

Tutor Answer

It's important to look back at the role "mammals" play in the argument. Although subtle, implied is that mammals were better able to defend against "angiosperms" then were dinosaurs. The former were able to "avoid [angiosperms]" and also had livers which could "detoxify such drugs"; the latter couldn’t do either. Dinosaurs, in other words, were susceptible to the "lethal effects" of angiosperms, but mammals were not.

The author's entire argument rests on the idea that contorted fossils equate to angiosperm induced death. Since dinosaurs were found in those position, the argument goes, then they must have died from the effects of angiosperm. Except according to answer choice (AC) A, mammal fossils have also been found in contorted positions. It begs the question: if mammals were better able to defend themselves against angiosperms, then why would they also have died in "contorted positions?"

AC A gives us reason to believe that contorted fossil positions are not indicative of angiosperm induced death. Why? Because angiosperm immune animals died in the same manner as non-angiosperm immune animals. The connection between contorted dinosaur fossil and the angiosperm extinction theory is tenuous at best, possibly even irrelevant. It's for this reason AC A is correct.

Student Question

I am confused because it seems like there is a correlation being drawn between crossing with the light and death. The stem states “more pedestrians are killed every year in North American cities when crossing with the light.” Isn’t that creating a correlation?

Tutor Answer

I completely empathize with the question. The stimulus does sound like it is describing a correlation. The problem, however, is that we don't actually know if a correlation has been established.

Establishing a correlation between "crossing with the light" and "killed crossing the street" requires showing a positive relationship between the two - or in other words, that the former increases the chance of the latter. We don't know if that is true. to make that determination, we would need to know how the total number of each group - crossing with vs against the light - compare to each other. Is one larger than the other? Is that size difference enough to outweigh the higher number of deaths associated with "crossing with the light"?

For example, what if the difference in deaths amounts to only 10 people? And what if, for the sake of argument, the "crossing with the light" group is 100,000 people larger than the "against the light group"? If true, than no positive correlation would exist. Crossing with the light would not be associated with a higher chance of death. In other words, no correlation would exist between the two.

In sum: to establish a correlation, one must show that it actually exists. The columnist did not accomplish that task. Insufficient evidence was provided for establishing a positive relationship between "crossing with the light" and "killed crossing the street."

Student Question

I made the mistake of choosing D originally, but in blind review I was able to correctly choose B. When it comes to weaken questions, should we be trying to look for an answer choice that attack the premises first versus the conclusion? In the video JY cites how D attacks the conclusion and not the premises, so I am just wanting to clarify that B is correct because it attacks the link the connects the premises to the conclusion that the florist made a mistake versus just denying the conclusion outright?

Tutor Answer

Yes, that's exactly right! The goal is to attack the link between the premise and the conclusion. Some arguments have stronger links, others weaker. That determination mostly is a function of gaps - or in other words, information which has been assumed but isn't explicitly stated. In this case, the author assumes that anyone who knows Drew well and sends him flowers must have done so with the intention to please. We don't know if that is true. A whole host of options exist for why someone who knows Drew well might not have a desire to please. Any of those options serve as alternate possibilities, each of which, if true, weaken the argument.

Alternate possibilities are key. Showing that an alternate possibility is true necessarily weakens an argument - it makes the conclusion less likely to be true.

One caveat: attacking the premise is not the same as attacking the link between a premise and conclusion. On the LSAT, premises must be accepted as factual truth. Correct ACs will never simply say "the premise is not true." Our task will only ever be to find the gaps in the link between the premise and the conclusion.

Student Question

Can you please explain this question? I feel like I don't know what I am doing wrong with this NA question or the other NA questions

Tutor Answer

It might help if we first briefly review the authors argument. We are told that "an expensive wine is not always a good wine." Why? Because "the reputation of the vineyard where the grapes originate plays a role in determining the price of the finished wine." A follow up question might be clarifying: why does "reputation...playing a role" mean that "an expensive wine is not always a good wine"? The stimulus does not provide enough information to answer that question. The connection between "reputation" and the conclusion, in other words, has been assumed.

The author has assumed that "reputation," by itself, is not always indicative of quality. Why? Because they have used "reputation...plays a role in determining [price]" to conclude that "expensive wine isn't always good wine," without explicitly saying the former leads to the latter. A gap, in other words, exists in the argument. An assumption is required to fill that gap.

Answer choice (AC) C helps fill that gap. It tells us that "the reputation of a vineyard does not always indicate the quality of its wines". Note what occurs when we negate that statement: reputation always indicates the quality of a vineyard's wines. If true, then it stands to reason that reputation should play a role in price - it always indicate a wine's quality, after all. The author's argument, in turn, would collapse.

AC C cannot be negated, because doing so invalidates the author's argument. Since it can't be negated, it must be true - or in other words, it is a requirement of the argument. This proves AC C is in fact a necessary assumption.

I highly recommend using the negation test on necessary assumption questions. It is the most reliable way to "prove" that an AC is in fact required by an argument. You can find more information about the "negation test" here at this lesson in the 7Sage Core Curriculum.

Student Question

I would like this to be explained a bit better - was stuck between A and B, chose B.

Tutor Answer

It might help to think of the difference between answer choices (ACs) A and B as akin to that between a necessary and sufficient assumption. Only the former is required by an argument. If it is not true, then the argument is not true as well. The same does not apply for sufficient assumptions.

We can apply that same reasoning to the politician's argument. In their telling, opposition to higher taxes makes someone a "better leader." Hence, Thompson is the best person to lead the nation, since he "opposes higher taxes". What is required for this argument? We must know that "opposition to higher taxes" is at least a factor in someone being a good leader. Because if not, then "opposition to higher taxes" is wholly irrelevant- it isn't even a factor. The argument, in other words, would collapse.

AC A collapses the argument. It tells us that "opposing higher taxes" isn't even a factor in someone being a good leader. There is no connection between the two. If no connection, then one has no reason to believe "Thompson is the best person to lead the nation." The only reason offered by the politician was Thompson's opposition to higher taxes. That reasoning, given what we are told in AC A, is now wholly irrelevant. It's for this reason AC A is correct.

AC B does not collapse the argument. Why? Because it doesn’t preclude "opposition to higher taxes" being a factor in someone being a good leader. All we know from AC B is that "[opposing] higher taxes" doesn't guarantee that one will be a good leader. But note what is still possible - it's still possible that "opposing higher taxes" makes the chances of someone being a good leader highly likely. And if highly likely, then it seems more than reasonable that one should indeed vote for Thompson. The politician’s argument, in other words, would be highly compelling. AC B does not preclude this possibility. It's for this reason AC B is incorrect.