The Toulmin argument model is a method for analyzing the back-and forth structure of a well-organized debate. It’s one way to think about structuring an academic paper, if your goal is to take an evidence-based stand on a cutting edge issue where well-meaning, well-informed experts look at the same problem and see different solutions.

To the ancient Greeks, the word “debate” did not mean belittling your opponent in order to win people over to your side or shouting down your detractors.

Instead, intellectual opponents would follow a rational plan for testing out competing premises, with the idea that the response from the audience could help everyone come a step closer to understanding what arguments are the most convincing (because they are supported by evidence).

To understand the following breakdown of a Toulmin argument, you should first know a few things about the subject matter.

• A split infinitive occurs when an infinitive verb (such as “to go”) is “split” by an adverb (as in “to boldly go”).
• One school of thought is that grammar is a list of errors to avoid and rules to follow.
• Another school of thought sees grammar as a description of how the most effective and influential writers and speakers tend to use a language.

We’ll start our Toulmin analysis with a Classical Syllogism: 

“Split infinitives are ungrammatical. Good writing requires proper grammar.  Therefore, writers should avoid split infinitives if they want to write well.”

Toulmin logic recognizes these three parts.

• claim: Writers should avoid split infinitives.
• reason: Because split infinitives are ungrammatical.
• assumption: Good writing requires proper grammar.

Leave the claim alone for now.  Add “grounds” to support thereason, and backing to support the assumption.
 

• claim: Writers should avoid split infinitives.
• reason: because split infinitives are ungrammatical. (why are they ungrammatical?)
  • grounds: In Latin, the infinitive was formed by a single word; hence, it was impossible to put an adverb inside the infinitive.
• assumption: Good writing requires proper grammar. (why do you say so?)
  • backing: The most successful, most widely-read writers follow standard rules of grammar.

The next step is to insert the opposing argument — the rebuttal.  For a longer paper, you can use the claim/reason/assumption model to examine each rebuttal, and your outline would grow much deeper.

• claim: Writers should avoid split infinitives.
• reason: because split infinitives are ungrammatical.
  • grounds: In Latin, the infinitive was formed by a single word; hence, it was impossible to put an adverb inside the infinitive.
    • rebuttal: The rules of Latin do not automatically apply to English.
• assumption: Good writing requires proper grammar.
  • backing: The most successful, most widely-read writers follow standard rules of grammar.
    • rebuttal: The fact that all the popular works follow standard grammar simply means that publishers and editors won’t distribute writing that doesn’t conform to the grammar rules they’ve learned.

Next, we handle the rebuttal by qualifying the claim (changing it to handle special cases as raised by the rebuttal). Then, we add defense.

• claim: Writers should usually avoid split infinitives, unless they are translating Latin (in which case they should always avoid them) or unless they are willing to risk the appearance of error (in order to achieve some effect).
• reason: because split infinitives are ungrammatical.
  • grounds: In Latin, the infinitive was formed by a single word; hence, it was impossible to put an adverb inside the infinitive.
    • rebuttal: The rules of Latin do not automatically apply to English.
      • defense: Although the historical reasons for adopting the rule may have been illogical, in the real world, many readers do in fact apply this particular rule to English.
• assumption: Good writing requires proper grammar.
  • backing: The most successful, most widely-read writers follow standard rules of grammar.
    • rebuttal: The fact that all the popular works follow standard grammar simply means that professors and publishers penalize all writing that doesn’t conform to the grammar rules they’ve learned.
      • defense: Philosophical opposition to strict grammar rules won’t help you get your writing approved by the professors and publishers (and employers and customers, etc.) who expect you to communicate in standard written English.

Note that each of the “defense” items could easily be turned into another claim/reason/assumption outline.

For example, the defense to the assumption above presumes 1) that the goal of a writer is to meet the formal expectations of professors and publishers, and further presumes that 2) standard written English is the way to meet those expectations.  A rebuttal to that would be the fact that some writing (such as ad campaigns, political slogans, song lyrics, etc.) is supposed to surprise, delight or motivate, rather than simply satisfy expectations.

The original author can handle many possible objections by adding qualifying terms such as “often” or “many,” and might eliminate a whole bunch of objections by narrowing the focus, as is the case in this revised syllogism, which responds to the objections raised in the analysis we’ve just worked through:

“A job candidate should aim to impress a potential employer. Some potential employers have been taught that split infinitives are signs of ineffective writing. Therefore, job candidates should avoid splitting infinitives in their resumes or cover letters.” 

But even the revised argument I’ve posted above is not immune to further objections.

How likely is that a candidate will actually encounter a potential employer who would consider a split infinitive to be an error? Does “some eployers” mean about 25% of the millions of employers in the English-speaking world? Who actually polled potential employers to determine how many emploeyers  is that chance? Would this advice apply equally to someone applying for a job as an English teacher, and to someone applying for a job as a restaurant manager? 

In a healthy intellectual environment, you would expect all parties to keep modifying their claims based on the merits of objections they encounter, with the goal of developing a set of best practices that represent our best understanding of the issue so far.

Those best practices are what we teach our students, even as experts continue to debate the fine points as they encounter new evidence and as new people come to the table with new questions to ask and knew ways of testing each other’s premises.

See Also

Dennis G. Jerz
Logical Argument in College Writing
As a fully-fledged member of twenty-first-century society, you will often be asked to make (and defend) difficult choices among complex alternatives. This web collection introduces the concept of logic in complex arguments.