PT24.S3.Q10 - all material bodies are divisible

TheBatman

I'm having trouble understanding the translation for the conditional logic to this question.

All material bodies are divisible into parts,

Material bodies --> Divisible

and everything divisible is imperfect.

Divisible --> NOT perfect

It follows that all material bodies are imperfect.

material bodies --> NOT perfect

It like wise follows that the spirit is not a material body.

Spirits --> NOT material bodies.

I chained this question up like this (which is wrong I think):

Material bodies --> NOT Spirits
Material bodies --> Divisible --> NOT perfect

There are two conditional arrows connected to Material bodies, but I represented it like this because I can't draw it out here.

The answer shows the chain like this:

Material bodies --> Divisible --> NOT perfect --> NOT Spirits

How did they come up with this chain?

https://7sage.com/lsat_explanations/lsat-24-section-3-question-10/

akistotle

This is a sufficient assumption question so they need the last chain in order for the argument to work!

All material bodies are divisible into parts,

Material bodies (MB) --> Divisible (D)

and everything divisible is imperfect.

Divisible (D) --> NOT perfect (/P)

It follows that all material bodies are imperfect.

material bodies (MB) --> NOT perfect (/P)

It like wise follows that the spirit is not a material body.

Spirits (S) --> NOT material bodies. (/MB)

MB --> D
D --> /P
MB --> /P

---

S --> /MB (MB --> /S)

What you need: /P --> /S
(S --> P)

TheBatman

Oh, I got it. Thanks!

BinghamtonDave

I've noticed a trend in the questions I have read of yours. Allow me to provide what I see as guidance on the overarching issue here. This is a sufficient assumption question. What this means is that what we are given in the stimulus is missing a link that will allow the argument to be internally coherent. Providing that link is sufficient to allow the conclusion to follow from the stated premises. This is a concept that took me awhile to really get down because in my daily life, I had never really stopped to find a sufficient assumption for anything. Unlike, say, flaws: which are everywhere around us: in newspaper articles, in political rhetoric, even in advertisements.

So, my advice for this question and other sufficient assumption questions is to use what we are given to prove what is being concluded. The conclusion on sufficient assumption questions will invariably be unproven from what we are given, our job is to fashion the premises provided to prove the conclusion. The skills necessary for this job are in my estimation: 1.comfortability with translation into conditional logic 2.practice with argument forms for a deeper understanding of what is at play. 3.an understanding of grammatical signals through practice with old problems.
Please also see the CC for lessons on these steps

For this question we are told:
If something is a material body——>divisible——>perfect
A tip from experience here is to put a slash through "perfect" to mean "imperfect" because sometimes the word for the negation in English of something confuses me when it comes time to negate that term. This is a personal preference.

The second sentence just tells us what we already know from valid argument form 3: https://7sage.com/lesson/valid-argument-form-3-of-9/

We are then told that if something is a Spirit----->Material Body
This is our conclusion. We know this because the stimulus says:"it follows" to indicate this.

So for this question we are given:
MB---->D---->P
And asked to take that and prove that:
S---->MB

How can we get spirits to be MB ? We can't just say: no spirit is a material body, that is a reiteration of what we are trying to prove: which is our conclusion. Given our evidence above, we can fail either necessary condition for the existence of MB and attach Spirits to either of those conditions! If we say that a spirit is Divisible we can prove our conclusion. What the test writers went for here is: S---->Perfect, which is a failure of the necessary condition of MB. Which is: a negation of "perfect"

Our last step here for review is to formulate the 4 possible correct answer choices for this particular problem, which are at bottom 2 possible correct answer choices and their contrapositives. For my review, I would then take these 4 possible correct answer choices and formulate them even further into sentences that indicate the logical relationship:" Everything that is a spirit if always perfect." There is an hour of learning for 24-3-10, get as many miles out of it as you can.

I hope this more complete explanation helps.
Don't hesitate to reach out with any further questions
David

TheBatman

@BinghamtonDave Thank you

MambaMentality93

That may very well be a stupid question, but how do you figure out which sentence is the conclusion? "It follows" is usually a good indicator that what follows will be our conclusion, but in this specific example we have "It follows" in the second sentence then "It likewise follows." Therefore, I kinda struggled finding the conclusion of that argument.