Did taking a course in formal logic help you with the LSAT? Forum

[rumky]

Did taking a formal logic course help you with the LSAT? I'm thinking of taking one next quarter if it will help increase my score. I'm in the high 160's/low 170's range, so even a few additional correct answers make a big difference. I took a TestMasters course but never got good at doing the "All P's are C's and some D's are C's" type questions- I can figure it out eventually, but it takes me awhile. I'm hoping a class in formal logic would help increase my speed with those questions.

What do you think?

[Peachykeen21]

I took one and it definitely helped with the sufficient/necessary and incorrect reversal type questions.

[brokendowncar]

I voted a little, but it might have been none. I took it about a year and a half before the LSAT, so most of the information faded. It didn't really take me a lot to pick up on the formal logic parts of the LSAT though, so maybe that was just the old stuff coming back.

I wouldn't tell anyone to take a formal logic class just to help with the LSAT, but I enjoyed my logic class. Take it if you think you might enjoy it, and then you might see some benefit too.

[rumky]

I'll probably audit it since I'm already taking a full course load. I think I will enjoy it and if it helps with the LSAT then that's even better! Unfortunately, the class starts at 8am.

[Pathfinder]

I felt that it confused me a bit. In the powerscore books they treat truth and validity as synonyms, as well as all words that specifically describe deductive and inductive arguments (suddenly they all reference the same thing). so that was a bit annoying for me. I feel like LSAT logic is a very tailored form of logic, and it is best to learn it straight from the course or workbook you are using. best of luck

[stavand]

It could help, but I didn't need it. Basic logic is all you really need: conditional, contrapositive, all vs none. My Lsat tutor and I did a logic section in prep for the games, although it is equally helpful on the LR. Whatever your decision, make sure you understand the basics very well, because on the LSAT, all you need to know is the basics, but you have to be able to visualize and master those basics enough to find the answer in a second.

That sounds like much, but there is a reason why most people don't finish any section of the test, and even more people don't even reach the last game.

Stavan Desai
172/3.75

[chosun1]

Some ppl debate whether they should take a formal logic class. Besides the obvious pointlessness of such a class to ppl wh are not taking comp sci or linguistics, there are rlly only a few elements that truly help on the LSAT. I'll save you the money and give you just the two most important things I learned from taking the class.

1. DeMorgan's Laws

DeMorgan's Law basically tells you how to convert a statement when a negative is attached. So for say an example that states " it is not the case that both A and B are used," you would write...

~ (A&B)

which according to DeMorgan's Laws is equivalent to...

~Av~B

this law actually helped me on one of the logic games in the Superprep Book.

2. Sufficient and Necessary

Now, most ppl don't get what is inherently the nature of the sufficient and necessary.

There are two ways I look at this:

a. sufficient leads to the necessary, but something else can lead to the necessary

ex. President signs a bill -> Becomes law

But something else can lead to a bill becoming a law, say "congress overrides the President's veto," thus this shows that there are other sufficient grounds for the necessary condition.

b. Premise and Conclusion
the most important thing I learned from a formal logic class is this and without this, I wouldn't have begun to solve many of the logical reasoning questions.
Sufficient and necessary is also parallel to premise and conclusion, that’s why ppl say in court lingo “There are sufficient grounds for this necessary conclusion”
Premise: A
Conclusion: B
Inference: A->B
This helps a lot of assumption, justify, strengthen, and conform principle questions.
Most ppl look at an assumption, justify, strengthen question and try to look for the new premise, new conclusion elements per the POWERSCORE method of Supporter answer choices. But sometimes these elements are not so recognizable. Take for example, a question like this…

Ex. Bob is very tired after he comes back home.
Therefore, Bob took a nap.
What most strengthens this statement?

There 1st sentence is the only premise to prove the conclusion in the 2nd sentence.
The answer choice would be not in similar words, but something to the equivalent of “ If is exhausted after work, he must go to sleep”

On Conform Principle questions, this Premise, Conclusion dichotomy is even more important.
Let’s say there was a principle…
Ex. If an action if not popular, then it must lack majority consensus or news media negatively reports on it.
Writing this out in FORMAL LOGIC abbreviation, it would be…
~ AP -> ~ MC v ~NMPR
( AP = action popular, MC = majority consensus, NMPR = news media positively reports on action)
You will never see a conclusion that states something “lacks majority consensus or news media negatively reports on something.” Why? Because these are simply the CRITERIA/GUIDING PRINCIPLES to judge whether the OUTCOME/JUDGMENT (action) is indeed correct
The OUTCOME/JUDGMENT must be the conclusion, so we take the contrapositive of the statement and match the answer choices to it.
So…
MC & NMPR -> AP
If an answer choices has ~AP, then it is not a correct answer choice.

[ram jam]

I took a class in my first year of undergrad and it did not help me at all. When I began studying for the lsat, I bought a formal and informal logic book, I cannot tell you if it helped though.

[EPluribusUnum]

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