In his 1959 book The Uses of Argument, philosopher Stephen Toulmin analyzed the components of effective argumentation. Toulmin’s analysis yielded one of the most useful formulas for organizing arguments. The first three components of the Toulmin argument are methods you use any time to you try to convince someone using an assertion combined with a “because” statement.

The Big Three: Claim, Data and Warrant


This is the thesis or central point you’re trying to prove. For instance, maybe your laptop was stolen from your dorm room and you want to argue that your university should install security cameras in residence halls. According to the Toulmin method, your assertion that cameras should be installed is the argument’s claim.


This is the evidence you put forward to support your claim. The truth of your claim might not be immediately apparent to your audience, so you need evidence to persuade them your claim is true. In this case you’d assert that the cameras should be installed because they would deter theft and make it easier for campus security to catch the thieves or recover stolen property. The theft deterrence and enhanced ability to catch thieves that the cameras would offer is the data, or evidence, that the claim is true.


Toulmin’s third component, the warrant, is an explanation of how the data supports your claim. Sometimes, as in the example above, the connection between the claim and the warrant is obvious, so you don’t need to state it. But in many cases, the evidence won’t speak for itself in terms of clearly supporting your claim. In such cases you’ll need to provide detailed analysis of HOW your examples prove your thesis. Also, when your warrant includes additional claims (or sub-arguments), you’ll need additional evidence to support those claims. In this case, you’d want to do research and find data showing that cameras in residence halls actually can deter theft or lead to apprehension of robbery suspects.

Supporting Cast: Backing, Counterclaim and Qualifier

These supporting components of the Toulmin Method make your argument stronger with more detailed defense and anticipation of audience disagreement.


This component is an extension of the warrant—additional use of evidence and logic to back up the explanation of how your data supports your claim. When you argue that your school should install dorm security cameras, your audience may not be aware of conditions that make the cameras necessary. So you’d want to explain the background that has created such a need: “In the fall semester, six laptops were stolen from Pencader Residence Hall alone, and the student lounge in Frost Hall was vandalized. Investigations of these thefts and vandalism have yielded no suspects.”


Since some of your readers may have objections to your main claim or supporting points, you’ll want to head off those objections. You do this by stating a counterclaim or counterargument and then offering a rebuttal—that is, a compelling argument against the objection. For instance, you could head off disagreements this way: “Some may object that tuition and housing costs are already very high, and purchase of extra security equipment would only raise such costs. But installing cameras in dorms would raise residential tuition by less than $30 a year, which is a small price to pay for preventing the theft and vandalism of student property.” If you don’t include the counterclaim and soundly refute it, you won’t be able to persuade readers who have that objection to your argument.


The qualifier component has a function similar to the counterclaim and rebuttal; it’s an effective way of preventing or dealing with objections. If one of your claims seems too strong, general or absolute, it may be less persuasive. So you use the qualifier to modify, limit, or qualify your claims—this should make your claims more precise or accurate. Qualifying statements use words such as sometimes, possibly, may, and perhaps for points on which there’s less certainty, and words like often, probably, or many when the writer is more confident about her assertion and its consequences. In the argument about dorm security cameras, you might qualify your claim this way: “Installation of dorm security cameras may not deter campus robbery completely or help to catch every campus thief. But the evidence shows that they often aid in tracking down the perpetrators, and sometimes even lead to recovery of stolen property.”