Q4 - Dental Researcher : Filling a cavity in a tooth is not

[gmatalongthewatchtower]

I was approaching this argument with any eye of "conditional logic". HEre's what I did"


Conclusion - Dentists should not fill a cavity unless the nerves inside the tooth are in imminent danger from that cavity.

OR (only if to if conversion)

If nerves inside the tooth are not in danger then doctor shouldn't fill the cavity

OR (contrapositive)

If doctor fills the cavity then the nerves inside the tooth are in danger (sounds funny!)

Premise 1 - Cavities are harmful only if the decay reaches the nerves inside the tooth OR (contrapositive)

Premise 1 - If Cavities are harmful then the decay reaches the nerves inside the tooth.

Premise 2 - Many times, if cavities are left untreated, then they never damage nerves.


I was completely lost at this point. I couldn't figure out assumptions using above work.

I could *logically* think of an assumption that the doctors will be able to predict imminent danger to the nerves, looking at cavities.

I was able to rule out, B,D and E answer choices. I see why C could be correct. But I am not able to rule out A.

CAn you please help me? Appreciate your help....


Thanks
Voodoo

[shaynfernandez]

Well, I don't know that it is possible to straighten this out perfectly with conditional logic because this argument uses words like "some" and "many" which aren't conditional friendly.

This is how I would map it.

FC= Fill cavity DT=damage tooth DRN=decay reaches nerve ID= imminent damage

FC--> DT--> DRN

Conclusion: FC-->ID

We can see we have a new term which is ID, so in terms of conditional logic in and of itself we would want to attach that somewhere in the chain. It has to be somewhere that allows us to concludes FC--> ID

So we could see the assumption as: DRN--> ID

However, like you said this won't get us exact wording because we dont diagram some and many which directly impact this argument and the way to reach the correct answeer.

Instead, I personally would recommend looking to the stem first and noticing that it's a Principle support question. PS questions tend to be general and describe something deserving as its conclusion. So they are not as set in stone as the conditional "if then" format.

However, we can eliminate A with areasonable understanding of the scope. A is pretty much telling a dentist how to do their job. We don't know based on the evidence presented that this would ensure a long term benefit.

[WaltGrace1983]

This is a tricky one and I think that more analysis of this would not be a bad thing (I am, of course, working from the principle that if it is not bad then one should do it )

Filling a cavity will cause inevitable damage
+
Cavities are harmful only if the decay reaches the nerves
+
Most times, the decay doesn't reach nerves
→
Dentists should not fill a cavity unless the nerves are in imminent danger of the cavity

So there is a lot of conditional language here. Let's see if we can break it down for practice and fun.

(Filling→ Inevitable Damage)
+
(~Decay reaches nerves→~Harmful)
+
(~Decay reaches nerves) in most situations
→
~Imminent Danger → ~Fill the Cavity

So what is all of this really getting at here? Well basically what it is saying is this: because most cavities aren't harmful, we shouldn't do something that will cause inevitable harm. In other words, we need to mitigate as much harm as possible. However, when approaching the answer choices, we need to pay special attention to that word "inevitable."

(A) This looks great! It is also conditional and is saying this: (Perform procedure → Procedure ~cause immediate damage). For the purposes of our argument though, I think it is more helpful to think of it like this: (Procedure causes immediate damage → ~Perform procedure). Yea! I like that. Let's keep it.

(B) Now we are talking stuff that doesn't matter. We don't care about prevention of cavities. It wasn't mentioned in the stimulus. All we know is that, if cavities exist, the stimulus talks about what occurs. This is suggesting that we should do something to prevent cavities but the stimulus doesn't evaluate to that.

(C) Uh oh. This one looks great too! The condition that is "only potentially harmful" is referring to having a cavity while a "method that is definitely harmful" is referring to filling that cavity. So this is saying that we shouldn't do what will cause definite harm in order to fix something that is only potentially harmful. That looks really good too. I'll keep it for now.

(D) Do we know if filling a cavity provides "temporary relief?" What if filling a cavity is incredibly painful and provides no relief? What if the relief isn't temporary? These are all questions that I am thinking that make me eliminate (D) because it is just too vague.

(E) "Constant surveillance?" This came out of left field and I have no idea how this is relevant. I am going to eliminate this.

So as most of you probably did too, I have a situation in which both (A) and (C) look good. What do I do? I compare the answer choices to the stimulus. I do not compare them to one another because that will just make them look really similar after awhile. It will confuse me. (A) and (C) look like they are saying the same thing...but are they? They cannot be! It is the nature of the LSAT! There cannot be two right answers so one of them is wrong due to some reason. Let's go in order and look at (A) again.

(Procedure causes immediate damage → ~Perform procedure). Hmm still looks good. Let me look the argument one more time...

Aha! The argument talks about "inevitable damage." Does this have to mean "immediate damage?" No! In fact, "inevitable" has the connotation (which doesn't mean that much but regardless...) of being later on. This is what makes (A) wrong. How did the LSAT trick us? "inevitable" and "immediate" are so alike in sound! They do this a lot. Be careful.

(C) is right.

[aznriceboi17]

The scope and 'inevitable' vs 'immediate' arguments against A make sense to me. Did people have any other reasons for rejecting A?

[ohthatpatrick]

Let me go ahead and provide an official explanation for this one. Great thoughts and questions so far.

A couple quick responses:

Typically, Principle Support questions do NOT involve diagramming the argument. However, this one definitely does contain a handful of conditional trigger words: "inevitably", "only if", and "unless".
Nevertheless, you're probably better off sticking with just understanding the argument core.

Typically, Principle Support answer choices DO involve conditional logic. Four out of the five here involve conditional logic (all of them but B).

Most correct answers involve matching half the answer to our premise and half the answer to our conclusion. However, you also need to verify that the Premise/Conc ideas are assembled in the correct
Prem --> Conc
order.

ARGUMENT CORE
Conc:
If the nerves aren't in imminent danger, don't fill a cavity.

Prem:
Filling a cavity causes harm.
Cavities are harmless if the nerves aren't threatened.

What I always do with Principle Support questions is focus on what my Conclusion is trying to prove ... "what idea should be on the right hand side of the conditional statement?"

Here, we're trying to prove: DON'T fill a cavity

If we quickly examine the answers just on that basis (does this principle have the power to prove my conclusion?), only (C) actually works.

(A) If a procedure is likely to be beneficial and it doesn't cause immediate harm, you should perform that procedure.

So this has the power to prove "you SHOULD perform that procedure". It doesn't have the power to prove "you SHOULD NOT perform that procedure".

Remember, if I have a rule that says:
"if you're rich, you eat kale"
that can only be used to prove
1. that someone eats kale
or
2. that someone is NOT rich

I can't use that rule to prove "you're rich" and I can't use that rule to prove "you don't eat kale".

(A) is gone.

(B) This advice tells us to focus on preventive care rather than wait to begin treatment. The conclusion and the premise were not about preventive care. This doesn't help us prove "you should not fill a cavity". This answer choice tries to preempt our entire discussion from happening by trying to prevent cavities from ever happening. That doesn't help us prove the conclusion; it would only help make the whole argument a moot point. Eliminate.

(D) If a condition is typically progressive, it shouldn't be treated with methods that only give you temporary relief.

This one is the closest wrong answer to actually working. It DOES help me prove that I "should NOT use a procedure that only gives temporary relief".

Can I match that up with the argument? Is "filling a cavity" a "procedure that only gives temporary relief"? Nope. Eliminate.

(E) If a condition is potentially harmful and it can't be kept under constant surveillance, then it should be treated.

This only has the power to prove that "we SHOULD do a procedure", not that we "shouldn't".

Our correct answer:
(C) If a condition is only potentially harmful, then it should not be treated using a method that is definitely harmful.

This can prove "we should NOT use a definitely harmful procedure".

Can I match that up with the conclusion? Is "filling a cavity" a "definitely harmful procedure"? Yes, the argument said that it "inevitably damages".

Let me verify by seeing if the left side of the conditional can match the premise. Is there a match for "a condition that's only potentially harmful"? Yes. Many untreated cavities never threaten the nerves and thus never become harmful.

Let us know if you have other questions about this one.

[aznriceboi17]

Hi patrick, thanks for your response! I think I realize why I had trouble with this question, and thought I'd write down my thoughts (to help myself and hopefully others who might have had the same issue).

The correct interpretation of (A), which you used, is:

Scope: Referring to the set of all procedures that dentists perform.

(likely to be beneficial) AND (not cause immediate damage) => should perform

However, my interpretation was to change the scope to consider only the set of procedures that are beneficial in the long run (which filling cavities would fall under), and writing (A) as:

Scope: Referring to the set of all procedures that dentists perform that are beneficial in the long run.

Should perform => does not cause immediate damage

The second interpretation, which can prove 'should NOT fill cavity', initially seemed more attractive to me since it captures the 'only if' language of (A) explicitly. However, it's not actually what (A) says since it allows for the existence of procedures that are beneficial in the long run and do not cause immediate damage to fall under the 'should not perform' category, whereas (A) does not allow for this.

[nmmizokami]

I too came to a decision about ACs A and C but without using conditional logic.

I ultimately eliminated A because of the phrase, "any procedure that is likely to be beneficial in the long term". The stimulus says that cavities are harmful "only if the decay reaches the nerves inside the tooth, and many cavities, if left untreated, never progress to that point".

Filling a cavity, therefore, cannot be categorized as a "procedure that is likely to be beneficial in the long term". If anything, it is likely to be detrimental, as a filling "inevitably damages some of the healthy parts of the tooth".