LSAT 16 - Section 2 - Question 06

This is a Necessary Assumption question which we know because the question stem is asking us for an answer the argument relies on. This means the correct answer must be true if the argument is going to work, and if it isn’t true then the argument’s conclusion absolutely cannot follow.

Think about how significant a development this is in human history. Where would we be without math? And these simple counting tools are the earliest known evidence of its origins. Nice. Ok, but even though we had abstract representation of numbers as far back as 20,000 years, it was only 5,500 years ago that “systematic methods” were invented to write numbers. Okay, what about it? Well, since systematic methods only developed 5,500 years ago, conclusion: computation only became possible at that time.

I don’t really know what a “systematic method” is here, or how it differentiates from simple tally marks, but I suppose this makes sense. Ever tried to do basic division using Roman numerals? Good luck. And even Roman numerals could qualify as a systematic method since they are within our 5,500 year timeframe. Anything even worse than that and I guess I can see how calculations would be out of the question.

It’s very likely a correct answer will need to preclude more basic, non-systematic methods of representing numbers from being able to perform calculations. If I plus I equals II is a calculation, then it seems perfectly reasonable to think these 20,000 year old counting sticks could be thought of as calculators. We don’t want to commit to searching for anything in particular, and we want to stay open to suggestion of other things we may not have realized could be necessary, but it is certainly okay here if we are expecting our answer to do something in this area.

Answer Choice (A) No, we’re not interested in challenging the origins of these tools. In fact, the stimulus does not seem to entertain any possibility that these things aren’t exactly what we think they are. This certainly has nothing to do with our conclusion, in any case, and doesn’t have to be true for the conclusion to follow.

Answer Choice (B) Well I would think this would be true. I mean, we’re literally talking about rocks here. I very much doubt every last type of rock, bone, or stick was used. But even if this is almost certainly true, it doesn’t absolutely have to be true. They could’ve marked up every stick, stone, and bone on the planet and it would still have nothing to do with whether or not they were performing calculations.

Answer Choice (C) Well, yeah, but so what? They seem to date back 20,000 years. Homo sapiens evolved way longer ago than that. But, who cares? What if they do? So what? This has nothing to do with whether calculations were being performed before 5,500 years ago when “systematic methods” were invented.

Correct Answer Choice (D) Oh! This looks great. This establishes a “systematic method” of representation as a requirement for any computation. Whatever a “systematic method” is and whyever these earlier number symbols don’t qualify as systematic, we know there were no systematic methods until 5,500 years ago. This must be true for the conclusion to follow.

Answer Choice (E) We don’t care why it was invented, only when. Maybe they were invented just for the pure fun and joy of it. If so, not a problem at all.