Justify System of Approach

[Kmikaeli]

Hey guys, I am having a bit of trouble assessing the information within the book in regards to Justifying the conclusion. The book state how the mechanistic approach must follow these rules: If new information is in the conclusion and not in the premises then the correct answer will have that element. second if both have the same elements then those will not appear as a correct answer choice, and lastly, if a premise contains new information that the conclusion does not have, then the correct answer will USUALLY HAVE IT. SO, how am I supposed to know whether the new element introduced in the premise is gonna be needed.

For instance, pg 319-320 of the Logical Reasoning book 2014 have two questions that are mind boggling. Question 2 and Question 4

Question 2 states that the "struggle early in life" is not required as a new answer because both premises contain that element. However, the conclusion does not and doesn't that mean based on step 3 of the mechanistic approach that I should include it?

Question 4 answer explanation states how element B is NOT included as a new element, but the conclusion does not include it...

A-->B--->notC
A--->notD
Correct Answer: notC--->notD
WHY does it not follow the mechanistic approach, it's really getting on my nerves.

[Dave Killoran]

Hi Kmikaeli,

I'm not sure I'm perfectly following your question here, but let me try to add some advice nonetheless

One of the things about the LSAT is that you can't reduce everything to a purely rules-based approach. There will be times when you have to assess what's occurring in front of you, and that's because the English language has so many variations that although 95% of what you see might be pretty straightforward, that other 5% can throw you for a loop! So, the answer to "how am I supposed to know whether the new element introduced in the premise is gonna be needed" is that you'll have to assess the answers and see what they give you. You can't know ahead of time what they will do, and even though in most instances they give you what you expect, there are exceptions (or rather, what appear to be exceptions; they still follow the rule, they are just much more clever and sly in how they make it look).

It might help to think about the Mechanistic Approach as relying on uniqueness: the elements that tend to show up in the correct answer are unique in that they appeared in just the conclusion or just a single premise. Anything that is duplicated in the argument—whether that's in two premises, or a premise and a conclusion—tend not to appear in the correct answer.

In item #2, then, "struggle early in life" is a duplicated element, so it's not likely to appear in the correct answer. Instead, take a look at what's unique in the argument (bolded below for convenience):

• Premise: Struggle early in life able to keep a good perspective on the world
  Premise: Struggle early in life Anderson
  
  Conclusion: Did not take success for granted Anderson

You see how what gets linked are the unique pieces of the argument? That's how this works, and so this does indeed follow the Mechanistic Approach.

#4 is trickier, but it too still follows the Mechanistic Approach. Let's look again at what's unique (bolded below):

• Premises: A B C
  
  Conclusion: A D

So, what gets linked in the right answer is indeed unique, but this problem requires you to think a bit more than say, #2. Because of the way the logic works—and you'll get more work with this type of thinking in Chapter Thirteen—B isn't needed (but, it could have been used in the answer; B and D, B, C, and D, or C and D could have been used).

The key is that when you see something that doesn't look right to you, stop for a bit and instead of thinking about why it doesn't fit, consider if there is a way that what you see could fit the technique or concept being discussed (this is especially so since I use the drills and problem sets to keep on teaching how the ideas work). The LSAT is a brutally tricky test at times, and there's no way to prepare for every eventuality. However, the book is giving you the framework to think how the test makers think, and it all fits together as we layer more and more info into the mix

Thanks and let me know if that helps!

[Kmikaeli]

Dave, you perfectly answered the mental dilemma I was having. You have been very insightful and helpful on my struggles. Now I understand that these are common techniques used, but in certain instances, the logical reasoning questions are established in ways that are a bit more complex or abstract than what the approaches tend to state. They may encompass tangential ideas, but language creates a sly process that takes practice to uncover.

[Dave Killoran]

Yes, that's exactly right, congrats! Glad I could help too

[Kmikaeli]

You're awesome. Thank you!