Strengthen the Argument
How to Support and Fortify a Logical Claim
A comprehensive guide to finding new information that makes a conclusion more likely to be true.
What is Your Mission?
Your goal is to find an answer choice that, if added to the argument as a new fact, makes the conclusion more likely to be true.
The "Wobbly Table" Analogy
The Argument
Think of the argument as a wobbly table. The premises are the legs, and the conclusion is the tabletop. It *mostly* stands, but it's not stable.
The Strengthener
A strengthener is a new piece of information (a wedge) that you add to *support* the argument and make it more stable.
It doesn't have to *prove* the conclusion 100%. It just has to *help*, even a little bit.
The #1 Way to Strengthen: State the Assumption
An argument is weakest at its unstated assumptions. The best way to strengthen it is to provide a fact that *proves* an assumption is true.
Visualizing the Support
The Best Strengthener:
"A recent market analysis shows that our company's workforce, industry, and project types are virtually identical to Company A's."
(This new fact fills the gap by confirming the assumption is true).
Three Common Strengthening Techniques
1. Confirm an Assumption
This is the most powerful method. Find the argument's weak link and provide a fact that proves it's solid.
Example: "This sample represents the whole population."
2. Rule Out an Alternative
Especially in causal arguments (X caused Y), an answer that rules out another potential cause (Z) strengthens the claim that X was the reason.
Example: "No other event (like a holiday) could explain the sales increase."
3. Add New Evidence
Provide a *new* fact that independently supports the conclusion, adding another "leg" to the table.
Example: "In addition to the ad, our social media engagement also tripled."
Decoding the Question Stems
They all ask the same thing: "Which new fact helps?"
- "Which of the following, if true, most strongly supports the conclusion?"
- "Which of the following, if true, provides the most support for the argument?"
- "The argument is strengthened by which of the following?"
- "Which of the following, if true, makes the conclusion more likely to be true?"
Key Word: "Most". Often, 2-3 options might strengthen the argument a little. You must find the one that helps *the most*.
Common Strengthen Traps
Don't fall for these common wrong answers.
1. The Premise Repeater
The answer choice just restates one of the premises in different words. A restated fact adds zero new support.
2. The Weaken
The answer does the exact opposite of what's asked. It attacks the argument instead of helping it. Always double-check your goal.
3. The Out of Scope
The answer introduces a new idea that is related to the topic but has no logical connection to the specific conclusion.
4. The "Inference"
The answer is a *conclusion* that can be drawn from the premises, not a *new fact* that supports them. (e.g., Arg: "A>B, B>C." Strengthener is *not* "A>C").
Practice Set 1 (4 Options)
Apply the techniques. Find the strengthener.
1. Argument: A city plans to reduce rush-hour traffic by adding new bike lanes. This plan will be successful. Which, if true, most supports this?
Assumption (Gap): The plan assumes people will actually *use* the new bike lanes instead of driving.
Answer (B) is the best strengthener because it directly *confirms* this assumption is true.
(A) is out of scope. (C) is irrelevant. (D) is a weakener.
2. Argument: Since Vitamin X was introduced, the rate of seasonal colds in our town has dropped by 30%. Therefore, Vitamin X is effective at preventing colds. Which, if true, most strengthens this?
Assumption (Gap): It assumes *no other factor* caused the drop.
Answer (D) is the best strengthener because it *rules out* the most obvious alternative causes (diet and exercise).
(A) is irrelevant. (B) is a good strengthener, but (D) is *stronger* as it rules out a direct cause. (C) is out of scope.
Practice Set 2 (5 Options)
Look for the answer that helps *the most*.
1. Argument: After the new security system was installed, break-ins at our store dropped by 50%. The new system is clearly effective. Which, if true, most supports this?
Assumption (Gap): Assumes no other factor (like a general drop in crime) caused the decrease.
Answer (B) is the *strongest* support. If crime *rose* elsewhere, but *dropped* at the store, it isolates the security system as the most likely cause. It rules out the alternative "general drop in crime."
(C) is a premise repeater (it just says *how* the system is effective, doesn't add new support).
2. Argument: To boost tourism, the city of Springfield will begin a large TV ad campaign. This will surely increase the number of tourists visiting Springfield. Which, if true, most strengthens this?
Assumption (Gap): The plan (TV ads) assumes that a *lack of awareness* is the problem, and that ads are the solution.
Answer (D) is the best strengthener. It directly confirms that the *problem* the ads are designed to solve (lack of awareness) is the *actual* problem.
(A) and (C) just describe the plan. (B) is neutral or a weakener. (E) is about *profit*, not about *increasing tourist numbers*.
Final Interactive Quiz
Test your mastery. Select your answers and check your score!
Summary & Next Steps
Key Takeaways
- Strengthen = Add a New Fact. You are adding a *new input* to help the argument.
- The #1 strengthener is a fact that confirms a necessary assumption.
- You can also strengthen by ruling out alternative causes or validating data.
- The answer doesn't need to *prove* the conclusion, just *help* it.
Practice Plan
- Daily Drills: Practice 5-10 strengthen questions daily.
- Find the Assumption First: Before you read the answers, pre-think the argument's *assumption*. The best strengthener is often right there.
- Mix & Match: Practice Assumption, Strengthen, and Weaken questions together to master the subtle differences.