LR Bible 2019 edition Chapter 6 pp. 206-207 (Revised)

[intent228]

Firstly I'd like to apologize for rehashing a subject that's previously been addressed. I have read three other discussion surrounding this (https://forum.powerscore.com/lsat/viewtopic.php?t=27721; https://forum.powerscore.com/lsat/viewtopic.php?t=10839; https://forum.powerscore.com/lsat/viewtopic.php?t=1868) but am still unclear.

This surrounds example question #4, particularly the sentence "Without such a stable and moderate axis tilt, a planet's climate is too extreme and unable to support life."

The book tells us to diagram as follows: PCE AS GI

However, I cannot rectify this with the Unless Equation™, which tells us "1. Whatever term is modified by 'unless', 'except', 'until', or 'without' becomes the necessary condition. 2. The remaining term is negated and becomes the sufficient condition."

Where is the negation in the above representation? Should it not be PCE AS GI? This would then make answer choice B a more clear contrapositive no?

*Admittedly, when I diagrammed the above statement I used a different representation for third sentence. Instead of PCE, I opted for L to represent life, interpreting the clause more simply as "no life". Giving me L AS

Even if there's good reason to avoid representing it as I did, I still don't understand the lack of negation.

(Edit: I found this issue again in a diagramming drill that's as follows: "Unless they find an eyewitness and put the defendant on the stand, they will lose the case."

I diagrammed as Win Case Eyewitness + Defendant on Stand / Eyewitness or Defendant on Stand Win Case

Answer key diagrammed as Lose Case Eyewitness + Defendant on Stand / Eyewitness or Defendant on Stand Lose Case

I see they're saying the same thing but it just doesn't seem to adhere to the Unless Equation™.)

[Dave Killoran]

Hi Intent,

While I'm hesitant to revisit a question that has been discussed a bunch already, let's take a look at a few things you said here which might help clear this up (while first noting that in the 2020 edition this problem appears on pages 212-213):

This surrounds example question #4, particularly the sentence "Without such a stable and moderate axis tilt, a planet's climate is too extreme and unable to support life."

The book tells us to diagram as follows: PCE AS GI

However, I cannot rectify this with the Unless Equation™, which tells us "1. Whatever term is modified by 'unless', 'except', 'until', or 'without' becomes the necessary condition. 2. The remaining term is negated and becomes the sufficient condition."

If you take a look at the book closely, you'll see chain you cite is the product of two sentences, Sentence 2 and Sentence 3. So, it's not dependent on a single sentence, but rather two connected sentences.

Turning to just the sentence you quoted (which was Sentence 3), let's look at it again:

• "Without such a stable and moderate axis tilt, a planet’s climate is too extreme and unstable to support life."
  
  Let's apply the Unless Equation:
  
  "Without such a stable and moderate axis tilt..." = AS (as in the book). Since "without" modifies the necessary condition, that becomes:
  
  AS
  
  
  Next, we turn to, "...a planet’s climate is too extreme and unstable to support life." This portion will be negated and placed in the sufficient condition, which becomes " a planet's climate is not too extreme," or PCE (planet climate too extreme) with a slash through it = PCE.
  
  That combination results in:
  
  PCE AS
  
  and there we have the diagram in the book as shown for sentence 3, which is the one under discussion

The issue here is that you are likely thinking about the meaning of each term, and trying to come to terms with "life" and "climate not too extreme," and getting the signals mixed. If you diagram this by the numbers, you can see the diagram above is supported. Can you use different symbols in your diagrams? Of course, and this is why negatives (or the lack thereof) are not a huge deal, as long as the meaning is the same. It's why I say elsewhere that something like "no money" could be diagrammed as "NM" or "M." I strongly prefer M because the negation is a simple "M," (whereas the negation of "NM" is "NM" (or "not no money"), which is confusing).

Please let me know if that makes sense!

[intent228]

Ah Dave, you dastardly logical machine, always so many steps ahead of us newbies. I appreciate the explanation, I can see clearly now how you came to your conclusions.

Will it help, only time will tell, but I know the closer I get to you the better off I'll be when I take this exam. Obviously I've still plenty work to do.

Best,

Intent

(p.s. lemme get a s/o on the podcast )

[Dave Killoran]

Haha, I'll try to on the next mailbag, which isn't far off lol!

The cool thing here is that sooner or later this will become second nature to you. You'll see it as a mechanical process, and once you have the terms handled, then you will be able to consider the meaning of the relationship more or less automatically. Right now, the mechanics are tripping you up but those will go away. It's like driving a car: using the gas and brake together at firs tis rough, but then after a while you don't even think about it anymore!

Cheers!