The Most Important Word on the LSAT

The LSAT is a wordy test — typically about 10,000 words.1 And every one of those words is important.

But over my sixteen years teaching people to ace the LSAT I’ve noticed that one particular word gives people more trouble than any other. It’s common on the test and people often miss its importance; in fact, this word causes students to miss more questions than any other. Can you guess what it is?

It’s only.

I know, I know, only isn’t exactly a ten dollar word. (Some might phrase it differently: It’s not an “SAT word”. Except that it is, but that’s a subject for another day.) But it is a four letter word, in every sense that matters. Over and over I’ve seen people miss the significance of an only and therefore miss a question they’d otherwise have gotten right, so I pay particular attention to it in my lessons.

Consider a couple of the of the things the word only can do. For one thing, only changes weak statements to strong ones. For example, there’s quite a difference between “I can fix it” and “Only I can fix it.” The first is a statement about one person (he can fix it), the second about that same person (he can fix it) and also about everyone else (none of them can). And since on many LSAT questions, particularly certain kinds of arguments (inference, assumption) and reading comprehension questions (“The author would be most likely to agree with which of the following?”) you’re looking for the weakest possible answer, while on others (“super-strengthen”2) you want a very strong one, only can loom pretty large in answer choices.

Only also has a powerful effect on conditional statements — in other words, on statements of the general form “If A, then B”, which are legion on the LSAT. An example to illustrate:

  • If you score 180 on the LSAT, you will be accepted to Stanford.
  • Only if you score 180 on the LSAT will you be accepted to Stanford.

The first statement is reasonable (though not quite true in practice), and if it were true it would be mildly good news. The second, on the other hand, would be terrible news if you had your heart set on Stanford. (Luckily it’s wrong; clearly many students get into Stanford without scoring 180.) What happened? In LSAT terms, we say that adding the “only” changed a “sufficient” condition (180 on the LSAT is enough — sufficient — to guarantee admission to Stanford) to a “necessary” one (the 180 is necessary, because without it you can’t get in). That’s a huge change in meaning. Further, this exact distinction (between necessary and sufficient conditions) is one of the two most common flaws in LSAT arguments, and perhaps the most commonly tested in questions that ask you to identify the flaw.[Note]I’ll talk about the other extremely common flaw in a subsequent post, but here’s a hint: It appears in almost every LSAT argument about health.[/note] And the most common way of sneaking a necessary/sufficient flaw into an argument is to slip an “only” into it.

I could go on (and as my students can attest, I do…), but by now you get the picture. Only is a big deal. In fact, most people can maximize their LSAT scores only by paying careful attention to it.

Notes

  1. In fact, the scored portion of the test (two sections of arguments, one of games, and one of reading comprehension) averages over 10,000 words; the experimental section is extra. Those with the misfortune (for some; good fortune for others) to encounter an experimental games section will face about 1,000 additional words, while an experimental reading comp section adds closer to 4,000.
  2. “Super-strengthen” questions are those that ask, in effect, what answer choice would absolutely prove the argument; the wording is usually something like “The essayist’s conclusion follows logically if which of the following is assumed?” This phrasing is so common that they’re sometimes referred to simply as “follows logically if” questions.