LSAT PrepTest 43 Section 3 Question 1 Explanation | Logical Reasoning

I didn't write the following blog post. It was already on the blog when I took over the URL. The following blog post may contain mistakes. -Steve

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Here's a Logical Reasoning question from the June 2004 LSAT.

A chain of phrases is helpful here (this is accomplished by underlining usually, but I'm writing it out for instruction's sake):

Patents promote inventing --> No patent = copy --> No financial incentive --> No inventions

We need to find the jump in the logic here, the place where the argument's reasoning breaks down with an assumption; this is our task on most assumption questions. That no patents would let people copy inventions and that the copying of inventions would remove the financial incentive for doing the R&D needed for inventing seems pretty true.

But is it true that, absent a financial incentive, inventing will cease? Not necessarily. Maybe inventors have some compelling non-financial rationale that would keep them inventing even without a financial incentive. So our pre-phrase of the required assumption's something like "inventors wouldn't invent without a financial incentive." We see that A fits pretty well, since it mentions financial incentives being the only compelling ones. Let's quickly go through the other choices.

A) Correct.

B) Out of scope, since whether the inventor or manufacturer makes more money is irrelevant to this argument. Either way, the argument wouldn't be made logical. What's needed is for financial incentives to be the only compelling ones.

C) Out of scope again; maybe the costs are substantial, maybe not. It doesn't really matter to the argument. Patents no longer existing and whether this would mean there would be no inventions isn't affected by this.

D) Out of scope since this argument is making a claim about what would happen if there were no patent rights; who deserves patent rights is thus irrelevant.

E) Wrong for the same reason as all the others. Costs of a patent right doesn't really matter here. The argument is making a claim about whether ending patents would end inventing, not about the relation of costs of obtaining patents to the benefits of having them.

Remember:

1) Look for the gap in assumption questions and use a chain of phrases.

2) Pre-phrase for greater speed and accuracy (don't write it down, just remember it).

3) Watch scope and eliminate choices that are out of scope or, in another words, don't directly bear on the argument's claim. Those cannot be required assumptions.