Logical reasoning PrepTest 135 · Section 4 · Question 18

The LSAT is trying to get you to pick this answer by doing two things. First, it lists some specific institutions - however, it ends with “other institutions,” thus showing that list is just to give some examples. Second, the stimulus states that these institutions “may” achieve public purposes, but that’s different than pointing out that other institutions fail at achieving them.

This answer is the general description of why a part-to-whole flaw is a flaw, and it reflects the stimulus. There, it states that an organization (the institutions) can have a property (public purpose) that not all of its members possess (each staff member having selfish motives). There is a shift between the stimulus (“each..does only”) and the answer (“not all”), but it’s in a direction that makes the logic work - a situation where no one has a certain motive certainly conforms to a generalization where not all people have that motive. (If that’s tripping you up, think about this - If we asked you to find a law school where not all of the students won an Olympic medal, would a school where no student won an Olympic medal qualify? Yep!)

The stimulus never discusses what the staff members claim are their motives, so this answer is out of scope.

The stimulus is about the staff members, not the founders, who could be completely different people. Also, someone could intend positive social consequences for selfish reasons - think of the person who does good so that they’ll go down in history as benevolent.

There’s no discussion of the founding purpose of these institutions, nor does the stimulus establish that the institutions are equally effective at helping the staff members reach their selfish motives.