QUESTION TEXT: How the pigment known as Han purple was…
QUESTION TYPE: Strengthen
CONCLUSION: The ancient Chinese probably discovered Han purple by accident while making glass.
REASONING: The same ingredients and similar processes were used to make white glass and Han purple.
ANALYSIS: The argument has implied that it’s possible that Han purple was discovered during the production of white glass. The makers of white glass were using the right ingredients, and a related process.
But the argument didn’t say if Han purple was invented in a place where white glass was made! If Han purple was invented somewhere without white glass, then the conclusion is almost certainly wrong.
The right answer strengthens the argument by at least showing that white glass could have led to the discovery of Han purple. It restricts the production of Han purple only to an area that also produced white glass.
Note: This is a very hard question. The correct answer is asking you to conceptualize an alternate possibility (that Han purple was discovered in an area without white glass) and then to recognize that answer A eliminates that possibility.
There would have been a simpler way of doing that. Answer A could have said “Han purple was invented in an area where white glass was produced”. But if the right answer had said that, then this question would have been too easy, wouldn’t it?
___________
- CORRECT. This eliminates the possibility that white glass and Han purple were produced in completely separate regions.
Note: This answer would have been equally strong if it said that white glass and Han purple were each produced all over China. The main thing is that it shows the two materials were produced in the same areas, therefore accidental discovery was possible. - This is just an irrelevant fact about how the materials were used. We care about how they were made.
- This doesn’t tell us about how Han purple was invented. It tells us how many people knew how to make it after it was invented.
- This shows that it would have been easy to make white glass. But that doesn’t prove anything about the production of Han purple.
For instance, the material to make wheels on suitcases was easily accessible for years, but we didn’t think of the idea. Upright wheeled suitcases were only invented in 1987. - This doesn’t explain anything. Maybe white glass objects were more durable than Han purple objects. Who cares? We’re only interested in what leads to the initial invention of Han purple.
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Muskan Sandhu says
Hi Graeme. Thanks very much for the explanations. I’m wondering why is it being assumed that Han purple was formed accidentally while producing glass and not the other way round–glass formed accidentally while producing Han Purple? It doesn’t say that glass predated Han purple, or is that implied by the use of the word “common” for glass?
TutorRosalie (LSATHacks) says
So you don’t have to prove the stimulus true on a strengthen question. You just have to strengthen it. A strengthens the link between purple and glass by showing they coexisted: it removes the possibility that Han Purple and white glass were made in different locations. And indeed, the word common does suggest glass predates Han purple. We know glass has been used by cultures worldwide, but Han Purple is unique to that Qin and Han dynasties. If the Chinese had invented glass the author would probably have remarked on that. (That is the kind of deference you give to the stimulus)
So the question ignores a bigger flaw: it’s possible there wasn’t even a link between Han purple and glass!