Hi @ddupray, thanks for your post. This is a Principle question.
As always, let's start with the stimulus. This one presents an argument; the conclusion is "Thus, even well-intentioned attempts to resolve the marital problems of friends are usually unjustified." What premise is provided in support of this conclusion? That the attempts of well-intentioned people to resolve their friends' marital problems "are usually ineffectual and thereby foster resentment."
Notice that the premise is about effectiveness ("are usually ineffectual," i.e., unsuccessful), but the conclusion is about whether an action is justified. These are two distinct concepts, and this question illustrates a classic LSAT trick - to shift, albeit subtly, from one concept in the premise to another in the conclusion.
The given premise here does not support the conclusion. The question stem asks you to select a principle that, if added to the stimulus, would strengthen the argument. You want to find the answer choice that bridges the gap in the argument. Answer choice (E) does this: "No actions based on good intentions are justified unless they also result in success." This bridges the gap between effectiveness and justification, thus strengthening the argument.
Hope this helps! Please let us know if you have any additional questions.
