PrepTest 80, Section 2, Question 13

Let’s break down this argument.

The author starts with a conditional premise: If laws are meant to contribute to happiness, then we have a framework for both critiquing the laws we have and proposing new ones. That framework would be evaluating an existing or proposed law’s impact on happiness.

Then they give us a conclusion: Because that first conditional premise is true, we can conclude that if contributing to happiness isn’t the purpose of laws, then we have no framework for evaluating laws.

Finally, we get the overall conclusion: Because the intermediate conclusion is true in their view, it must be that existing laws are considered legitimate just because they’re laws.

Hot garbage.

The flaw creeps in during the intermediate conclusion. The author tells us what happens if laws are meant to contribute to happiness. But then they make a conclusion based on what happens if laws aren’t meant to contribute to happiness—in their premise, the author only told me about the “if” side, not the “if not” side.

In other words, if laws are meant to increase happiness, then we have a framework. If we don’t have a framework, then that isn’t the purpose of laws. But that’s not the same as saying if that isn’t the purpose of laws, then we don’t have a framework—that confuses sufficient and necessary.

It’s a Flaw question, so I need the answer choice that says the argument treats a sufficient condition as a necessary one.

Let’s see.