## Formal Logic and Conditional Reasoning in LRB

Prepare for the LSAT or discuss it with others in this forum.
dkb17xzx

Posts: 403
Joined: Wed Jan 20, 2010 6:25 pm

### Formal Logic and Conditional Reasoning in LRB

Is it important to go over the formal logic section and the chapter on conditional reasoning (Ch-6) in LRB. Or will I be OK with simply focusing on the individual question types and the corresponding chapters? I'd love to hear from past test takers and the ones who are preparing for the LSAT right now.

Thanks.

Kabuo

Posts: 1114
Joined: Tue Aug 31, 2010 8:53 am

### Re: Formal Logic and Conditional Reasoning in LRB

This is hard to answer without knowing how well you do on these types of questions. FWIW, I didn't get the LRB til I had already taken ~15 Prep Tests, so I had a fairly good idea of what I struggled with. I just did chapters on the two question types I struggled with (Strengthen and Most Strongly Supported) and then missed 2 total LR questions on the October exam.

Underdog180

Posts: 39
Joined: Wed Dec 29, 2010 4:11 pm

### Re: Formal Logic and Conditional Reasoning in LRB

Funny thing is, I was about to ask the same question. I am currently reading the LRB and came across the Conditional Reasoning and Formal Logic chapter. Since they aren't considered "question types" according to the bible, I wasn't sure if I should skip them. I do know Conditional Reasoning is somewhat part of Logic Games, but should I just work on that in the LGB later on instead? I guess, the question is, how crucial is Conditional Reasoning and Formal Logic?

Kabuo

Posts: 1114
Joined: Tue Aug 31, 2010 8:53 am

### Re: Formal Logic and Conditional Reasoning in LRB

I don't remember if these are even the names for question types that LRB uses, but "what can be properly inferred," some "must be trues," and "must be falses," use conditional reasoning. I personally attack these questions intuitively, because when I try to diagram them, I usually mess them up and affirm the consequent or something. A good grasp of conditional reasoning could be extremely helpful for some of the nastier parallel reasoning questions though. If you struggle with any of these types, I'd suggest you read that section. In fact, unless you're on a time crunch or something, just read the section. It's not going to hurt you, and it might help you.

Kurst

Posts: 446
Joined: Mon Aug 09, 2010 9:33 pm

### Re: Formal Logic and Conditional Reasoning in LRB

I am confused. Less than two weeks ago, Underdog180 inquired about the merits of conditional reasoning, and the creator of this thread -- dkb17xzx -- responded by furnishing a couple of formal logic links. I thought dkb17xzx's response indicated that for him formal logic (as well as conditional reasoning) were concepts worthy of study, but apparently I thought wrong, for here we are again. dkb17xzx is questioning the necessity of understanding formal logic and conditional reasoning, and Underdog180 has apparently forgotten the sage advice he received less than two weeks ago.

If you do not understand the concepts of formal logic and conditional reasoning, you will not perform well on the LSAT.

As with everything pertaining to the LSAT, this has been discussed:

Conditional Reasoning and Formal Logic
Chapter 11 in Logical Reasoning Bible

Jeffort

Posts: 1888
Joined: Wed Jun 18, 2008 4:43 pm

### Re: Formal Logic and Conditional Reasoning in LRB

Kurst wrote:I am confused. Less than two weeks ago, Underdog180 inquired about the merits of conditional reasoning, and the creator of this thread -- dkb17xzx -- responded by furnishing a couple of formal logic links. I thought dkb17xzx's response indicated that for him formal logic (as well as conditional reasoning) were concepts worthy of study, but apparently I thought wrong, for here we are again. dkb17xzx is questioning the necessity of understanding formal logic and conditional reasoning, and Underdog180 has apparently forgotten the sage advice he received less than two weeks ago.

If you do not understand the concepts of formal logic and conditional reasoning, you will not perform well on the LSAT.

As with everything pertaining to the LSAT, this has been discussed:

Conditional Reasoning and Formal Logic
Chapter 11 in Logical Reasoning Bible

I noticed that apparent paradox as well. Kurst, we should call you the encyclopedic archivist of TLS and the forum search button should be renamed 'ask Kurst'!

As for the topic, YES, study and learn conditional reasoning and formal logic. Conditional reasoning is one of the two most heavily tested concepts/type of logic/reasoning on the LSAT, with cause and effect logic and reasoning being the other. Therefore it is important to know to get a good score.

EarlCat

Posts: 606
Joined: Mon Mar 12, 2007 4:04 pm

### Re: Formal Logic and Conditional Reasoning in LRB

Jeffort wrote:As for the topic, YES, study and learn conditional reasoning and formal logic. Conditional reasoning is one of the two most heavily tested concepts/type of logic/reasoning on the LSAT, with cause and effect logic and reasoning being the other. Therefore it is important to know to get a good score.

^This.

Conditional reasoning is the last topic you should ignore when studying the LSAT. Anyone who tells you otherwise should be flogged.

dkb17xzx

Posts: 403
Joined: Wed Jan 20, 2010 6:25 pm

### Re: Formal Logic and Conditional Reasoning in LRB

Kurst wrote:I am confused. Less than two weeks ago, Underdog180 inquired about the merits of conditional reasoning, and the creator of this thread -- dkb17xzx -- responded by furnishing a couple of formal logic links. I thought dkb17xzx's response indicated that for him formal logic (as well as conditional reasoning) were concepts worthy of study, but apparently I thought wrong, for here we are again. dkb17xzx is questioning the necessity of understanding formal logic and conditional reasoning, and Underdog180 has apparently forgotten the sage advice he received less than two weeks ago.

If you do not understand the concepts of formal logic and conditional reasoning, you will not perform well on the LSAT.

As with everything pertaining to the LSAT, this has been discussed:

Conditional Reasoning and Formal Logic
Chapter 11 in Logical Reasoning Bible

Kurst,

Thank you for your response. CR and formal logic are indeed "concepts worthy of study." I studied them at the beginning using the links I posted as well as the TLS article. However, the links and the article provide a brief overview of the subjects concerned. The LRB chapters, on the other hand, are very detailed. As such, I asked specifically about plowing through those chapters. Under no circumstances,as your mistaken assumption asserts, am I "questioning the necessity of understanding formal logic and conditional reasoning." Thank you for the links.

To all others who responded, thank you.

magicman554

Posts: 201
Joined: Sat Oct 30, 2010 2:02 am

### Re: Formal Logic and Conditional Reasoning in LRB

READ IT. I bet there are bits that you will learn from. For instance:

"Either Jim or John will go to the party."

Most people gloss over this and think "Jim or John, but not both, will go to the party." This would be wrong, and reading that section would clarify why.

Every point matters on the LSAT, so make sure you have a flawless understanding of something as basic as formal logic, because, I'm sorry to say, it gets a lot trickier.

dkb17xzx

Posts: 403
Joined: Wed Jan 20, 2010 6:25 pm

### Re: Formal Logic and Conditional Reasoning in LRB

Magicman,

Thanks.... based on the advice here, I'll definitely read through the chapters.