Analyzing arguments
In everyday life we rarely encounter arguments in clean form. Reasons and claim are jumbled together, some things remain unspoken, and rhetorical embellishments hide the actual structure. To analyze an argument means to free it from this packaging and make its logical core visible.
Reconstructing an argument
A reconstruction usually follows these steps:
- Find the conclusion. Ask: What does the speaker want to convince me of? Signal words such as therefore, hence, thus help. Often the conclusion stands at the beginning or the end.
- Collect the premises. Ask: Which reasons are put forward for the conclusion? Signal words are because, since, for.
- Add hidden assumptions. Ask: What additionally has to hold for the reasons to carry the conclusion? These implicit premises are often the real weak point (see Recognizing hidden assumptions).
- Put it into standard form. Write the premises down numbered and the conclusion below them. This makes the structure testable.
Statement: "You shouldn't eat this mushroom, it could be poisonous, after all you don't know it."
Reconstruction in standard form:
- (Premise) You don't know this mushroom.
- (implicit premise) Mushrooms that one does not know could be poisonous.
- (implicit premise) What could be poisonous should not be eaten.
- (Conclusion) You should not eat this mushroom.
Applying the Toulmin model
For more complex arguments the Toulmin model helps, because it not only separates premises and conclusion but also makes the bridge between them and the limits of the argument visible. One questions the argument step by step:
| Question | Toulmin element |
|---|---|
| What is being claimed? | Claim |
| What does it rest on? | Data (facts) |
| Why do these data carry the claim? | Warrant |
| What does this warrant rest on? | Backing |
| How certain is the claim? | Qualifier |
| When does it not hold? | Rebuttal |
Statement: "Harald is presumably criminally responsible, for he is 16 and thus over 14, and in Germany one is criminally responsible from the age of 14 — unless an expert opinion certifies that he lacks maturity."
- Data: Harald is 16 years old.
- Claim: Harald is criminally responsible.
- Warrant: Whoever is over 14 is criminally responsible.
- Backing: Section 19 of the German Criminal Code (StGB) sets criminal responsibility from the age of 14.
- Qualifier: "presumably".
- Rebuttal: unless an expert opinion certifies a lack of maturity.
From breaking down to evaluating
Only the reconstruction makes a fair evaluation possible. With the exposed structure you can check in a targeted way:
- Are the premises true or at least defensible?
- Are they relevant to the conclusion and do they support it sufficiently? (see Characteristics of good arguments)
- Does the warrant really hold, or is there a questionable assumption hidden in it?
- Does a rebuttal apply that undermines the argument?
On the next pages we go deeper into tracking down hidden assumptions and practice the analysis on concrete examples.