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Blueprint?

It's important to distinguish what is being offered as a reason for the conclusion, and what is simply a description of the thing we're talking about -- which the author isn't presenting as a reason supporting the conclusion. Consider this: Mary likes studying. Thus, she's a good student. Would you agree that "If someone like's studying, then they are a good student" is necessary? If so, why wouldn't this narrower version be the extent of what's necessary: "If someone named Mary likes studying, then that person is a good student." The author doesn't have to assume people named John who like studying are good students, or people named Paul who like studying are good students, right? After all, the argument was just about a person named Mary. If something about that previous paragraph strikes you as odd, it's supposed to! Although it's true that the argument was about Mary, the fact that she was named Mary had nothing to do with the author's reasoning. What mattered was that this person -- whatever her name was -- likes studying. So the author's assumption really is broad -- Anyone who likes studying is a good student. If that were not true, the author's premise cannot be sufficient to prove the conclusion. Now consider this other argument: I have a roommate. Because she likes studying, and her name is Mary, she must be a good student. In that argument, her name being Mary is now part of the reason I believe she's a good student. In this version, the assumption is no longer about anyone who likes studying. It's about anyone who likes studying and is named Mary. Does this make sense? This is why I view "Anything with wings can fly" as a necessary assumption in the example argument. The fact that we're talking about pigs is not offered as a reason for the conclusion -- it's just the subject my argument happens to be about. The reason I think the thing we're talking about can fly is that it has wings; the fact it's a pig doesn't play a supporting role. That's why the broadest form of the necessary assumption is "Anything with wings can fly." (Keep in mind this statement implies various other ideas that are necessary -- All pigs with wings can fly, some pigs with wings can fly, the fact something is a pig does not prevent it from flying, etc.)

Hopefully lol 😂

See PT140.1.22 to see that the LSAT would consider "anything that has wings can fly" a necessary assumption. Is there something about the way I explained it in the video that you disagree with? If "anything that has wings can fly" were not true, then the premise is not sufficient to prove that pigs can fly. This is why "anything that has wings can fly" is necessary for the argument. It's necessary in order for the premise to be enough to guarantee the conclusion.

@@LuminateLSAT this question puzzled me when a took that PT as well. Could you please elaborate how can something which can be negated and conclusion in the stimulus still follows could be necessary. My assumption was that if we negate something and conclusion cannot follow anymore that is necessary. I would really. Appreciate your clarification on this issue. Thanks so much Kevin.

@@LuminateLSAT wouldn’t conclusion still follow if we assume atleast some things which has wings can fly. That is why i was confused that Anything might not be necessary because it can be negated and the conclusion still follows. Let me know if i am mistaken here Kevin please.

@@lakhvirsingh-lm4kj It looks like you think that the negation of a necessary assumption needs to disprove the conclusion. That's not correct. The negation just needs to show that the premise cannot guarantee the conclusion. If we negate "anything that has wings can fly," then the premise offered -- pigs have wings -- cannot, by itself, guarantee the conclusion anymore. That weakens the argument, which means the argument must assume "anything that has wings can fly." You're right that the conclusion could still be true -- it's still possible that pigs can fly even if some things with wings cannot fly. But the key point is that if you negate "anything that has wings can fly," the given premise cannot guarantee that pigs can fly. The negation of a necessary assumption just needs to show that premise cannot guarantee the conclusion -- it doesn't need to show that the conclusion is impossible to be true.

Good question. The phrase "practice may have potentially negative consequences" in the correct answer is a reference to the practice of eating dairy foods and its potential consequence of increased risk of heart disease. So, I don't see it as a counterexample to the point of this video, although I do see how it seems close to one. To be a counterexample, the correct answer would need to mean "even if the avoidance of dairy increases the chance of maintaining good health..."

You raise an interesting point -- my interpretation of the argument is that the author uses cost/benefit reasoning to support the recommendation. Why else would the author bring up the lack of public trust in her decision other than the idea that there's something bad about having the public lack trust in a judge's decision, and that this should count as a reason for resignation? Thus, by pointing out that the harms outweigh the benefits, we have shown that the premise doesn't guarantee that the judge should resign. You're right that the negation would not make "should resign" impossible. What if, as you point out, there's a policy that any judge who loses the trust of the public should immediately resign. But the fact that the author would need to respond by bringing up that rule or by citing to some other principle in my view shows that the negation weakens. The author would need to defend her argument by citing to things outside the premise, which shows that the premise she gave isn't enough to prove the conclusion. My take on this does require me to believe the author's mode of reasoning was cost/benefit. In theory, the author could have been relying only on a moral principle, without any thoughts about costs or benefits. I'm not sure that's a reasonable interpretation though. I suppose it depends on what we take to be the "default" kind of reasoning given the premise. "The job I was just offered pays more than my current job. Thus, I should accept the new job." Is this necessary: "The benefits of taking the new job are not outweighed by the costs." It is if we think the author was using cost/benefit reasoning. In theory the author could have been operating under the theory that money is the only that that matters, not as part of a cost/benefit calculus, but as a moral principle in deciding one's job. I don't think that's a reasonable default, though.

@@LuminateLSAT Thanks for the quick response! That really helped clarify my point of confusion :)

That's right -- to improve at LR we have to always try to understand how the premises support the conclusion. We can't just identify the conclusion and assume that we'll be good.

Do you mean Question 2 #3? The answer choice about how the early-rising group's short term memory compares to the memory of the average person? Just want to make sure that we're evaluating whether the answers are weakeners, strengtheners, or neither. So the video isn't considering whether we can conclude any of the answer choices. It's about whether, if the answer choice were true, that has any affect on the argument. Comparisons to the average person don't affect the argument, because we already know that the early rising group experienced an increase in short term memory compared to the non-early rising group. Even if the early rising group started off with a stronger short term memory compared to the average person, we still know they increased their short term memory over the semester.

@@LuminateLSAT Yes, that's the one. Thank you, this was helpful! I completely misread the question, but this explanation and your video explanation make total sense.

Sorry, that part isn't on TH-cam because LSAC doesn't let us show real problems (except for a select number and you have to pay a ton of $$$ to show them).

lmao this is me with my exam next week

Yes, usually = most. Same with "probably."