The way I see this in actual questions is having a set of facts which might include the following: Most people have an irrational suspicion of pasteurized milk. Then the stimulus says the set of facts is proven to be false by some new study and it will ask us what conclusion can be made.

When a most statement is negated, you have to remember that it is improper to assume that most people don't. In this case, saying most people don't have an irrational suspicion leaves out the possibility that half of the population doesn't have the irrational suspicion. If half the population is suspicious and the other half isn't that is still a negated version of the original premise, "most people have an irrational suspicion of pasteurized milk."

Changing poopy diapers on time makes one a good parent.

So if change then good parent. change-> good parent.

To negate this or to deny the relationship we can say it is possible to change poopy diapers on time and not be a good parent - change and /good parent. This is different from the contrapositive form, because the contrapositive is still logically equivalent. Negation disrupts the relationship between two conditions. Its not the case that changing poopy diapers makes one a good parent. This means you can be in the sufficient condition without being in the necessary condition which if you think about is completely different from the rule I laid out in my first sentence.

All A are B. To negate this claim we must deny the relationship, not the existence of a set. The way we think about this relationship is the quality of being "all". To deny the relationship, we would say some As are not B.

All jackfruit is splendid. J->S

Negated: J <-s->/S meaning some jackfruits are not splendid.

Every time I see my baby cousins at the pool I think, we must teach them to swim.

@Dbarsemian Hey, so I believe it is general in the sense that we don't know what the harm is and if children are actually being harmed. All we know is that children consume more. That doesn't mean that they are being more harmed. They might be, but that's an assumption.

Also, what are the measures taken? Is using TMD a new measure the government implemented because a previous measure caused harm? We don't know. I think it's easier to see how E is wrong based on how it is really hard to trigger this sufficient condition because of the lack of information in the stimulus and how the conclusion in the end doesn't get us closer to knowing that the practice is unacceptable. The generalization is just a part of that bigger picture.

I was so stumped as to why B is the correct answer choice, but now it helps me to see it in this analogy.

Once a month, the well-being of Mr. Fat Cat's first-grade class is surveyed and some months, it is reported that well-being is very low. It is a well-known fact that bullying causes some students to feel sad and being sad is a symptom of low well-being in the class. Every day, Mr. Fat Cat's class goes to recess. Sometimes Mr. Fat Cat's shredded, intimidating brother, Mr. Yoked Cat supervises recess.

Furthermore, several students bully the rest of the class by calling them names and refusing to play with them. This causes those students to feel sad.

Answer choice B which says A-Acid slows down the deterioration of cognitive abilities which is a symptom of Alzheimers is like a key that unlocks the puzzle.

The equivelant of answer choice B in this Mr. Fat Cat argument is if I added this information: The presence of Mr. Yoked Cat on the days which he does supervise has the effect of restraining the bullies from their typical mean behavior. See how adding that information demonstrates the relevance of that premise to the idea that sometimes the students bully other students which causes sadness which causes low reports of well-being?

Pack your bags boys, it's breeding season. We're going home for a family reunion!

@landonekatz I agree. I was about to write down this comment, but saw you already did. I chose correctly, but felt like J.Y. missed the most clear reason why we can't choose E. Sure, I guess it is possible that the antibiotic is in the exception, but that is much more confusing since the stem says no antibiotic right now is in that exception.

If my cigarettes are paid for, SIGN ME UP

If anyone else is confused about the contrapositive form here, this might help.

What confused me initially is I was thinking:

A -> B

contrapositive : /A -> /B ...so how the hell does that capture the sense of if A does not precede B then A can't cause B.

The conditional looks like this:

If A can cause B -> then it must be the case that A preceded B

contrapositive: Should A NOT precede B -> A CANNOT cause B.

In this form where you take the A -> B to be the sufficient cause and the chronology of A and B to be the necessary cause, you can tell see clearly how the negation of the A to B timeline requires the A causing B negation.

Here is a question #feedback

I understand the implied logic of the formal argument all A are B and most A are C; therefore, some B are C. Could we stretch this to say it is a valid inference that most B are C?

I think the answer would be no, but I would like to understand this better.

Think of this example. All really cool guys own a red sports car. Most really cool guys are tennis players. Therefore, most red sports car owners are tennis players.

The reaons I believe this is not valid is because All A are B only tells me that the subset A is completely consumed by the superset B. I can not make a "most" statement about superset B because I do not know how large that superset is.

@futurelawyerlol No, it can not. All is not a range and it is not ambiguous. With all, we can confidently be sure of each member of the set.

When we are talking about many, we know we have a large amount, but the largeness of that amount is unclear. All is a total amount.

Here is how I think about it.

Many monkeys at the Brooklyn Zoo are dancing could mean 15, 20, 30, or 100. It just has to be more than the lower boundary for "some" which is 1.

Most monkeys at the Brooklyn Zoo are dancing means at least 51% of them. If there are 100 monkeys then at least 51 are dancing.

All monkeys at the Brooklyn Zoo are dancing is a non-ambiguous statement with no range. It is simply total.

@Igotthis123 If you take the claim M is adopted as true it GUARANTEES that the N and O are both adopted. Given the lawgic form, M -> N and O, you can not just have M->N. The necessary clause is N and O are adopted.

Think of the NYC example. I could say, if one lives in NYC then they are Yankees fan and they live in the USA. Let's just take all these claims to be true and you end up with : NYC -> Yankees fan and live in USA

You would not say, if one lives in NYC then I know they are a Yankees fan, but I am not sure if they live in the USA. Based on the claims I established, one would have to be be both a yankees fan and live in the USA. Hope this helps.

I was feeling some confusion earlier about sufficient and necessary conditions. My biggest takeaway that helped me get over this hump is that you need to get over how weird the necessary condition sounds and just accept the form of the argument.

Think about the previous Anderson v. King County argument. The necessary condition is showing that the defining characteristic of a class is an immutable trait. In order to achieve the sufficient condition (qualifying as a suspect class) then it is necessary to prove that immutable trait.

The zombies argument can be confusing because the necessary condition of the market crashing, seems like one that can happen because of other reasons. Necessity does not imply the condition at hand is limited to the sufficient claim. Think about the subset, superset forms of this argument. The market crashing is the superset. There are other ways for the market to crash that do not involve the subset of zombies. Maybe there is a smaller subset in the market crashing superset which is a weird virus goes around causing people to shrink into ant-size!

This helps with questions like #5. Typically one group (A) will be easier to identify in these sorts of questions. I saw the phrase "than are accustomed to" and I knew that was one of the comparatives. I marked it A. You have to think about category which you know so far - on very cold days. Therefore since no other kinds of days are mentioned, I called the missing comparative group "all other days".

"When politicians resort to personal attacks, many editorialists criticize these attacks but most voters pay them scant attention. Everyone knows such attacks will end after election day..."

I understand how people could go both ways with the referential in the first sentence, "them". I'm chalking this up to being a poorly written, confusing sentence. Them can refer to "personal attacks" in addition to "editorialists".

The case is stronger for "personal attacks", but at this point I just want to justify my original thought which was referring to "editorialists".

While the Tiger Argument has a convincing premise which supports its conclusion, the Disney argument is stronger because it leaves no gaps for any other possibility besides Walt having offered propitiations. My eye immediately caught on to the phrase "can cause" in the Tiger argument and I knew that while it does increase the likelihood of the conclusion, it is not as strong of an argument as all tigers always attack people. The Disney argument offers multiple premises which not only increase the likelihood of the conclusion but make the conclusion true beyond a doubt. We know that Walt has access to the pass and has never prostrated himself to anything before. The Disney argument differs from the Tiger argument because it eliminates other possibilities and has a chain of reasoning.