Argument Anatomy: Premises, Conclusions & Indicator Words
Recap: From Orientation to the First Real Skill
Day 1 laid out the shape of this plan and the shape of the test. Today is where the actual studying starts, and it starts at the smallest unit that everything else is built from: a single LSAT argument. Every Logical Reasoning question — all 30-plus question types you'll meet over the next nine weeks — is a variation on "here is an argument, do something with it." If you can't reliably find the conclusion and the premises, every later skill sits on sand.
CS Bridge
Think of an LSAT argument as a function: premises are the inputs, the conclusion is the return value. Indicator words ("therefore," "because") are like type annotations — usually there, genuinely helpful, but the function is still well-defined even when they're missing, and you have to be able to infer the signature from the body when they are.
1. What Counts as an "Argument" on This Test
An LSAT stimulus is either an argument (someone is trying to persuade you of something, using evidence) or a fact set (a collection of true statements with no persuasive point). Most stimuli are arguments. The tell for a fact set is the absence of any claim that depends on the other claims for support — it just describes a situation. This distinction matters immediately: several question types (Main Point, Flaw, Strengthen, Weaken) only make sense against an argument, and a small number (some Must Be True questions) are just as happy with a fact set.
2. Conclusion and Premise Indicators
Conclusion indicators signal "this is the point I'm trying to prove": therefore, thus, hence, so, consequently, it follows that, clearly, this shows that. Premise indicators signal "this is evidence I'm offering": because, since, for, given that, after all, this is due to. When you see one of these words, you've been handed the argument's skeleton for free — use it.
3. Intermediate (Sub-)Conclusions
Some arguments have a claim that is a conclusion relative to what comes before it, but is itself used as a premise for a further claim. Example: "Overtime increases errors [premise]. Therefore, tired employees make more mistakes [sub-conclusion]. So the new no-overtime policy will reduce defects [main conclusion]." The main conclusion is always the one everything else supports; a sub-conclusion supports something else in turn. This is the single most common way test-takers misidentify the "main point" — they stop at the first "therefore" they see.
4. Context, Background, and Opposing Views
Stimuli often open with background information or state an opposing view before the author's actual argument: "Some critics argue that X. But in fact, Y." The material before the pivot word ("but," "however," "in fact") is not the author's position — it's what the author is arguing against. Watch for this pivot; it's the most reliable signal for where the real argument starts.
5. The "Why Should I Believe That?" Test
When indicator words are absent or ambiguous, ask of each candidate sentence: "if someone asked me why I should believe this, could I point to another sentence in the stimulus as the reason?" The sentence that other sentences support, but which nothing else in the stimulus supports, is the main conclusion.
6. The Two Most Common Traps
First, mistaking the opposing view for the author's conclusion — easy to do when the opposing view is stated first and at length. Second, mistaking a sub-conclusion for the main conclusion — easy to do when the sub-conclusion sits closer to where you expect the "point" to be (often mid-passage) and the actual main conclusion is a single sentence at the end.
Practice items on this page are curriculum-authored in LSAT style; they are not official LSAC questions. Real drilling happens on LawHub — see the assignment below.
Official Drill Assignment
No PT sections yet — you want your diagnostic (Day 6) unspoiled. Instead: on LawHub, open the free "Official LSAT Prep" lessons under Logical Reasoning → Argument Structure, and work through the conclusion/premise identification drills there. These are LSAC's own teaching material and don't consume PrepTest questions.
Original Practice Items
Q1. Which sentence is the main conclusion? "Rising rents have pushed many young families out of the city center. Since family departures reduce school enrollment, the city's two smallest elementary schools will likely close within five years. City council should therefore expand rent stabilization."
Q2. A stimulus opens: "Proponents of the new zoning law claim it will lower housing costs. But in the three cities that adopted similar laws, average rents rose." What is the author's position?
Q3. Classify: "Because sea otters prey on sea urchins, and sea urchins graze on kelp, regions with healthy otter populations tend to have denser kelp forests." The kelp-forest claim is a:
Peek into Tomorrow
Reading Comprehension passages are, structurally, extended versions of exactly what you learned today — longer arguments with more moving parts, multiple viewpoints, and an author whose own position you have to track. Tomorrow builds the passage-level version of the same skill.