The Hard Facts on the LSAT

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The LSAT is a test of logic before anything else.  It asks you to dissect arguments, make deductions, and pick apart flaws.  Why then does so many of the questions seem to stump even the most logical thinker?  Mostly, it’s because the LSAT goes out of its way to make sure that all the facts you’ve learned before the test don’t help and may even hurt you.

lsat factsFor a moment, imagine yourself in the place of the test makers.  You would have to come up with a way to evaluate the thinking of each test taker, without favoring people who have expertise in a particular subject matter, all with an 100 question multiple choice test.  Sound tough? You bet.

The only way to take away the subject matter bias is to remove the need for any background information.  In theory, you could know not one single fact about the world around you and still score a 180 on the test if you have the English and logic skills.  However, it’s not possible to write a test that deals in practical situations such as those posed in the logical reasoning section without dealing in specific facts.  The test makers thus find themselves with a problem.  Background knowledge is both necessary and absolutely forbidden.

So here’s the solution they came up with.  The facts are directly given.  It’s like being given an open book test, if only you know where the book is hidden.  Consider this completely made up argument:

A dog will always chase a cat it discovers in its territory.  My neighbor’s dog, Spot, saw my cat, Kit, lurking about his doghouse.  Therefore, Spot will try to bite Kit.

For the moment, ignore the argument itself.  Instead, find the “facts” that the LSAT makers have created.  First, they provide the fact that dogs always chase cats discovered in their territory.  Clearly, this isn’t actually true.  My cat is much more of a bully than any dog she meets.  But that doesn’t matter; that knowledge is a fact that I’m bringing in from the outside world, which the LSAT works to make sure isn’t relevant.  Instead, we need to believe that all dogs in this situation will always chase cats.  It doesn’t matter if it’s a four pound wisp of a dog and a seventeen pound alley cat.  That dog WILL chase that cat.

Now that we’ve found a fact that we either disagree with or aren’t sure about in real life, the test is going to create a trap in the answer choices.  If this asks for something that will weaken the argument, one option would likely be “Spot does not always chase cats he finds on his territory.”  This does NOT weaken this argument.  Based on the facts, this answer choice is actually impossible. It couldn’t weaken anything; it can’t even exist in LSAT-land.

Similarly, the second fact we’re given we need to absolutely believe.  Claiming that “Kit is a good hider” does not weaken the argument because we know that she’ll be found.  “Spot is a great tracker” doesn’t strengthen the argument for the same reason.

The only idea we can and should possible argue is the conclusion reached based on the facts in created.  The author here has concluded that Spot will try to bite Kit.  Let’s determine if this is justified.  We can reasonably reach the conclusion that given the facts, Spot is going to chase Kit.  Had that been the author’s conclusion, the argument would have been completely sound.  The only issue here is that the author jumped from chasing to trying to bite.  The only possible assumption here is that to chase is not the same as to try to bite.

This principle can be applied more generally by determining what facts are given to you in each argument.  Once you’ve identified these facts, you can more easily separate your outside knowledge from the actual facts in the question.  From there, finding assumptions, flaws, and a range of other features of the argument are much easier.