- Wed Jun 14, 2023 2:29 pm
#102123
Hi Jude,
This is a case where the "only extremely minor differences" actually make all the difference in the world, so to speak.
On the LSAT, a difference of one or two words can be critical, as happens here.
Answer D is actually a valid argument and therefore definitely doesn't contain the flaw in the stimulus.
Answer D describes a valid conditional argument.
"The only fruit in the kitchen was pears" can be diagrammed
FK -> P
"the pears were not ripe" can be diagrammed
P -> not R
"thus none of the fruit in the kitchen was ripe" can be diagrammed
FK -> not R
This is a valid conditional argument. Importantly, the term "unripe" here is the same in the conclusion as it is in the premise. In other words, it doesn't matter how we define "unripe" relative to other fruit.
The premises tell us that the pears were unripe and they were the only fruit in the kitchen, so it logically follows that all of the fruit in the kitchen were unripe (which is just another way of saying that none of the fruit in the kitchen was ripe).
The argument in the stimulus changes terms from "tall tulips" in the premises to "tall plants" in the conclusion. And this seemingly small change actually makes the argument invalid because "tall tulips" are not necessarily "tall plants" in the same way that "jumbo shrimp" aren't necessarily "large crustaceans."
