There is no causal language in the first sentence and JY keeps insisting that it is causal. The last sentence does have a causal link established. But that is the only place where it exists. Someone feeling comfortable approaching another is a cause for long-term friendships beginning. But that's the only causal language and relationship here.

JY misread answer choice A when he was describing it. "only" in answer choice A is not showing a necessary condition. It is not saying "only M". It is saying the evidence only showed the fact that M is able to cure athletes foot. A is the correct answer. But that explanation in that part of the video is incorrect.

A tripped me up because it says observations. plural. I counted one observation. That it's taboo to eat domestic animals that provide labor. I did not count "therefore worth more alive than dead" as a unique separate observation. It seemed rather to me as a mini conclusion supported by the only actual observation.

A is certainly correct and nothing else in it seems questionable. But in a time crunch, I'm trying to identify falsehoods in the prompt to eliminate answer choices and I said "there were not observations, there was one observation." Clearly I made a mistake and it was compounded when I later guessed wrong because I hadn't rightfully identified all of the things that were wrong with all 4 other options.

Was I flatly wrong to say there was only one observation?

If there was only one, would that not matter? In other questions, answer choices distinguish between whether one or two different premises are supporting a conclusion. I thought a similar thing was happening here.

I had to choose between which was more wrong, the plural form of observation, or "more plausible" in option choice C. Clearly it is not necessarily more plausible. But it just didn't seem clear to me that there was more than one observation.

Also, I agree that C is wrong, but I don't agree that rejecting the reasoning of a hypothesis is not compatible with stating the conclusion is unwarranted. It seems totally consistent. If I reject the reasoning of an argument or hypothesis, that means I don't accept it as valid. It does not mean I declare it to be false. C does not say reject the hypothesis, it says reject the reasoning. Saying a conclusion is unwarranted means that you reject the reasoning that was used to reach that conclusion. It is consistent. Though, I agree that this does not mean that the other hypothesis are more plausible. "more plausible" is the main thing in my mind that renders C to be an incorrect answer. I wish JY didn't gloss over C just because it didn't fool him like E did.

There are two arguments here. Who is to say which argument contains the main conclusion? I know it's not asking for the main conclusion. But what if it were? How could I separate one argument from the other? Is it always the case that if one argument is followed by "Similarly, (argument 2)" then argument two contains the Main Point and not argument one? Is it even important to make that distinction?

I'd argue that this argument requires another necessary assumption, which is: You can not develop new important types of medicine that you have not already developed with substances that you have already discovered. I was unsure if A was correct, because I was thinking, "well so what that it is the same, (not different) from the other substances? Maybe we could use it to develop new drugs we haven't considered yet." But if it was the same, then we could develop those new drugs from those same substances we have already discovered as well. But we are saying that important types of medicine will never be developed.

Meaning if the rainforest burns down completely, you couldn't even develop new important medicines with the substances you already had either. And if you couldn't do that, then you couldn't develop them with the new substances that turn out to be the same. So it actually is necessary that they differ.

Another necessary assumption is that substances of medicinal value can be used to develop important types of medicine.

There are so many different necessary assumptions almost always if not always. For example, to be a good baseball player, you must be able to stand, you must be able to breath, you must be alive. There are nearly infinite necessary assumptions. And sometimes finding one can help you find the others. I wasn't totally sold that A was necessary until I convinced myself that the first one I proposed here is also necessary. But once I identified it, it seemed so obvious to me that A is necessary.

I think that goes to show that hunting for the right answer is very difficult and not always fruitful in this type of question. Because there are so many possible correct answers it might not be the one you are looking for that shows up in the choices.

Here is my problem. What does it mean for one thing to be significantly more similar to something than a third thing is to that second thing? What is significant? I am going to throw out some made up numbers.

Lets say prehistoric human ancestors are 98 percent similar to Neanderthals.

And lets say Humans are 96 percent similar to Neanderthals.

That two percent seems significant to me. I would say they are significantly more similar to Neanderthals than Humans are. But why is that necessary to imply that they didn't interbreed? Maybe they did and there was enough time that the ancestors, even though they interbred, shifted to only 96 percent similar?

In a blind review, I could eliminate the other 4, but I could not get myself to accept this one. It just does not seem necessary to me. Necessary means the negation makes it impossible. But I negate it and I can still think of plenty plausible scenarios to make the conclusion potentially valid.

Negating C we get that the ancestors were significantly more similar to Neanderthals than Humans were to Neanderthals. And? Natural divergence could explain that right? Humans evolved over time and slightly shifted to be less similar to Neanderthals than they used to be. Maybe if there was interbreeding, the effect of making the DNA more similar was overcome by other factors in the hundreds of thousands or millions of years that followed.

Ancestors are significantly more similar to Neanderthals than we are to Neanderthals and we are significantly different from Neanderthals. I see no dilemma here. That seems totally plausible and reasonable to me.

One statement says more, one doesn't. I think the "more" is tripping me up. I don't see how that necessarily implies that we are significantly different from our ancestors.

The negation of the answer has to make the argument fall apart to call the answer a necessary condition.

So when you negate an answer choice and the argument does not fall apart, you know you have not found your necessary assumption. Negate A and we get, there is at least one wild large mammal species that we didn't try to domesticate. And what does that imply about the argument? not much at all if anything. It doesn't really matter. Our response to that statement is "So? who cares?" We were already working with a subset of animals, never did it require that all wild mammals were included in the attempts.

The negation test really does seem like the strongest way to verify these answers.

The second rule is not what they need to do to get the award. It's what they can do to get the award.

My issue with this type of question is, when I read A and it is exactly what I was looking for, how confident can I be to select it and move on to the next question immediately to save time as opposed to reading the other options to be sure that there is not somehow an even better explanation? I'd love to be able to ignore the other options and move on to save 20 seconds, but this isn't a must be true question. Can I ever be sure that what I have read can't be beat?

The A&/B construction threw me off until I added this. The symbol for "there exists", ∃.

There exists something that is A and not B. ∃A&/B.

We aren't saying it is true that A and /B. We are saying there exists a scenario in which A and /B coexist.

This tripped me up because all of the options look like wrong answers. E seems like such a leap. We go from some subset of doctors sometimes treat patients rudely to say it is strongly supported that Doctors (therefore all doctors) foster the perception that they don't care about their patients. It seems so weak. And the question is asking for strongly supported. Add the word "Some" at the beginning of E and I'm all in. But to just say "Doctors" seems like such a stretch that I don't know how we could say this is strongly supported.

For the problem in the game: "Louv claims we carry at least thirty animal senses, some we do not know we have. These senses, he says, can reconnect us to nature." It asked what "These senses" is referring to. The answer it gave is "at least thirty animal senses." I interpreted the sentence as referring to the other prior referential statement "some we do not know we have" I know that "these senses" is referring to the senses mentioned. But I thought it was specifically referring to the subset of senses that the passage says we do not know about as opposed to all of the thirty senses mentioned first.

"Fat cats trained by Parisian divas sing lullabies." Is this equivalent to the conditional statement, "If you are a fat cat that is trained by Parisian divas, then you sing lullabies."? Giving that "being a fat cat trained by Parisian divas" is the sufficient condition, and "sings lullabies" is the necessary condition?

"Over the past several years, increases in worldwide grain production have virtually ceased." I'm curious why this is not considered context and rather is considered a premise. I understand that the next statement after this one is a subsidiary conclusion that is used as premise for the main conclusion, and that this subsidiary conclusion, "further increases will be extremely difficult;" is supported by the premise immediately following it. Are we saying this first sentence in the prompt is also supporting that? Or are we saying it is supporting the main conclusion? What distinguishes it from merely context?