A common misconception on the LSAT is that “principle questions” are a thing. In fact, the word “principle” appears in multiple question types which you should treat very differently. The most important thing to look for when you see the word “principle” is whether the principle points up or down. Some questions (PSAa or Rule Application questions) give us a principle in the stimulus and ask us to apply it down to the answer choices. These are akin to Most Strongly Supported questions, where we must be cautious of overstrong language and stick only to inferences supported by the stimulus.

This question (a PSAr or Find The Rule question) does the opposite: it presents a bunch of principles in the answer choices and asks us to apply them up to the stimulus in an effort to justify the argument. These are akin to Strengthen questions, where overstrong language is completely fine and we’re hoping to bridge any gaps in the argument we can find.

PSAr questions tend to follow routine patterns, and our approach can therefore be similarly routine. First, it’s critical to identify the argument’s conclusion and the premise(s) that seek to support it. In a shockingly high proportion of PSAr questions, the correct answer will take the form: Premise → Conclusion.

Like in normal Strengthen questions, though, it’s also important to note any common flaws you see, or (especially) subtle jumps from one concept to another (e.g. from talking about athletes to talking about professional athletes). Correct answers that address weaknesses like these are common as well.

Let’s start with the conclusion, which features some referential phrasing: “That proposal is unacceptable.” This bit alone gives us enough to anticipate the rest of this question’s structure: the stimulus is gonna describe the situation we’re in, then someone’s gonna make a proposal, and then for the Columnist’s conclusion to make sense, we’ll need a general principle that says “There’s [something about our situation] that makes it unacceptable to [do the stuff you’re proposing].”

Okay then, let’s pin down the situation and the proposal:

Situation: Our water utility got approval to levy a tax to fund a dam.
Proposal: Let’s not build a dam. Let’s use the money to build roads instead.

Anticipating the rule means looking at the situation and the proposal and plucking out some features to plop into the template from earlier. For example:

It’s unacceptable to [use money for roads] when we [got that money to build a dam].

That’s a pretty good one. I mean, it’s kinda the one. In the real world, it’s generally bad to raise money for one purpose and then use that money for a different purpose.

But here are a few others just to reinforce the formula:

It’s unacceptable to [build roads] [before building a dam].
It’s unacceptable to [not build a dam] if [you get approval to build a dam].

Those two are fine, they just match our real world intuitions less well.

Note: As you evaluate the stimulus, you should also pick up on the value judgment leap across the is-ought gap. You can’t jump from descriptive premises about how things are to normative conclusions about how things ought to be. In a PSAr question, this means our principle will take us from one side to the other – something like “When things [are] this way, they [ought to be] that way.” This dynamic turns out not to be a difference-maker in this particular question, because every answer choice provides a bridging principle. (Verify that for yourself! It’s good practice!)