Logical Reasoning Guide Questions

[cyruswhittaker]

I've been making my way through the LR Guide and and am finding it to be very helpful and really helping me to craft a more defined approach to the section. However, I have some questions that I've marked along the way and thought maybe I could post them and get some feedback. I'll have more time to go back later and review the questions I had but this was one of them:

On page 206, with the question from September 2007, #22, the solution goes into each choice by getting rid of the wrong choices based on the conditions for each principle.

However, it seems to me that a very quick and efficient approach would be to isolate the necessary/sufficient conditions of the principle:

(wholly truthful) --> (true + made w/o int. dec.)
(int to dec. OR refrain from clarifying)--> (lie)

From the basis of sufficient conditions, it would seem that all of the choices MUST be incorrect except D. Afterall, these are two things we cannot determine from the passage:

*IF a statement is wholly truthful (since only necessary conditions were provided)
*IF a statement is not a lie (since by the contrapositive, the second statement makes this the sufficient condition)

Since this approach seemed so efficient as well as applicable to similair types of problems, I didn't know if there was a reason why it wasn't mentioned.

Is my reasoning correct here or is there something I missed?

[noah]

Interesting question.

I think that approach is just fine, and I'd argue that it's embodied in the approach in the book. By noting that we have to check both boxes, we're in effect saying that the two conditions are necessary (for being truthful).

For the lie (or at least something not wholly truthful), either condition is sufficient.

Probably the reason the authors put it the way they did is that it is an approach that simplifies the problem without formalizing it. But, fire away with yours!

[dtangie23]

I bought the logical reading guide as well and I really liked it. You guys really have a knack for boiling things down and getting to the heart of stimuli.

I do have one question, though. Why does the book not explicitly differentiate sufficient and necessary assumption questions? The book includes sufficient assumption practice questions, but never really goes into the difference between the two.

For something that we speak of so much on the practice test forum, I was surprised to not see it in Chapter 5 of the book.

[noah]

That's a great question. The short answer is that we've decided to start emphasizing the difference, and the newest edition of our LR book will go into that (and our course already does).

The longer answer is that our intent has always been to present a curriculum that is relevant to people already scoring well on the LSAT and that are looking to score even higher. When we looked at what high-scorers actually do, we found they don't generally differentiate between the two assumption types, so we decided not to push the issue. As we've expanded and absorbed more teachers, we've asked them to help us shape our curriculum, and some of them have gotten a lot out of teaching necc. vs. suff. (and, more importantly they feel their students have benefited), and so we've decided to include the topic. Even those teachers who haven't been teaching it feel that working the distinction is a good exercise in understanding assumptions, even if a more general approach to assumptions - as you see in your edition - does the trick most of the time.

Shoot me a personal e-mail in a couple of weeks and I'll be happy to mail you a copy of the new assumptions chapter so that you can compare. I'd be interested to hear what you think.

[dtangie23]

Sounds good. Thanks for the response!