Welcome to Constructing Arguments!

In your Thinking Skills journey so far, you have spent a lot of time taking other people's arguments apart to see how they work. Now, it is your turn to be the architect! This chapter focuses on providing reasons in support of a conclusion. This is the most fundamental part of building an argument: if your conclusion is the "destination," your reasons are the "engine" that gets you there.

Don't worry if this feels a bit daunting at first. Constructing an argument is a skill that improves with practice, and by the end of these notes, you'll know exactly how to pick and present reasons that make your case unshakeable.


1. What is a Reason?

In Thinking Skills, a reason (sometimes called a premise) is a claim that provides support for a conclusion. It tells the reader why they should believe your main point.

The basic structure of any argument looks like this:
Reason 1 + Reason 2 \(\to\) Conclusion

Important Note: In the Thinking Skills exam (especially Paper 4), you will often use evidence from the provided documents as your reasons. The syllabus treats evidence and reasons as the same thing when you are constructing your own case because you cannot verify the facts yourself during the exam.


2. The "So What?" Test: Ensuring Relevance

The most common mistake students make is providing a "fact" that is true but doesn't actually help prove their conclusion. To avoid this, use the "So What?" Test.

Imagine you want to prove this conclusion: "Schools should start at 10:00 AM."

Reason A: "Most teenagers need 8-10 hours of sleep for healthy brain function."
The Test: So what? Well, if they start later, they are more likely to get that sleep. This does support the conclusion.

Reason B: "School buildings are often painted in neutral colors like beige."
The Test: So what? This has nothing to do with the start time. This does not support the conclusion.

Key Takeaway: A reason is only useful if it directly strengthens the case for your specific conclusion.


3. Making Your Reasons Persuasive

To build a high-scoring argument, your reasons should be strong and credible. Here are three ways to ensure your reasons carry weight:

A. Use Principles

A principle is a general rule or value (e.g., "People have a right to privacy" or "We should protect the environment"). Using a principle as a reason makes your argument feel more "universal."

B. Use Evidence and Data

If you are writing for Paper 4, you will have documents full of statistics and reports. A reason backed by a number (e.g., "75% of accidents are caused by fatigue") is much harder to argue against than a vague statement (e.g., "Lots of people are tired").

C. Focus on "One-Sided" Strength

Did you know? In Thinking Skills, when you are asked to construct an argument, it is not considered a weakness to be one-sided! Your job is to persuade, not to give a balanced "on the one hand / on the other hand" debate. Every reason you provide should point in the same direction: toward your conclusion.


The way you phrase your reasons matters. You want to make it "easy" for the examiner to see how your reason leads to your conclusion. Use indicator words to signal your reasoning:

  • "Because [Reason X], it follows that [Conclusion]."
  • "Given that [Reason Y], we must conclude that [Conclusion]."
  • "Since [Reason Z], the only logical path is [Conclusion]."

Quick Tip: If you find it hard to connect a reason directly to the main conclusion, you might need an Intermediate Conclusion. You can learn more about this in the chapter on "Structure reasoning using intermediate conclusions."


5. Common Mistakes to Avoid

Even top students sometimes fall into these traps. Keep an eye out for them!

  • Contradicting yourself: Make sure Reason 1 doesn't accidentally prove that Reason 2 is wrong.
  • Repeating the conclusion: This is called "circular reasoning." If your reason is just your conclusion rewritten in different words, you haven't actually provided support.
  • Assuming too much: Don't leave a massive gap between your reason and your conclusion. If the connection isn't obvious, explain it!

6. Summary Checklist for Your Exam

When you are asked to provide reasons in support of a conclusion, ask yourself these four questions:

1. Relevance: Does this reason actually support this conclusion? (Apply the "So What?" test).
2. Clarity: Is the reason stated clearly and simply?
3. Persuasion: Is this the strongest reason available from the evidence provided?
4. Consistency: Do all my reasons work together to point to the same conclusion?

Key Takeaway: Your reasons are the foundation of your argument. A conclusion without reasons is just an opinion; a conclusion with strong, relevant reasons is a powerful argument!