In everyday speech an argument is a quarrel. In writing it means something more useful: a claim supported by reasons and evidence, offered to readers who are free to weigh it and say no. Argument is how people who disagree can still reason together, which makes it one of the central skills of public life. This level covers how to build a written argument.

The thesis

A written argument usually centers on a thesis, the main claim the whole piece supports. A good thesis has three qualities. First, it is arguable, meaning reasonable people could disagree with it; "Libraries lend books" is a fact, not a thesis. Second, it is specific enough to defend in the space available; "Society should value education more" is too vague to test. Third, it matters to someone. Announcing a topic ("This essay will discuss libraries") is not a thesis at all, because it announces a subject but makes no claim.

The Toulmin model

In 1958 the British philosopher Stephen Toulmin published The Uses of Argument, which offered a way of mapping the parts of everyday arguments. Writing teachers have used it ever since. Its core pieces are these. The claim is the position you want the reader to accept. The grounds are the evidence offered for it. The warrant is the assumption that links the evidence to the claim, and it often goes unstated. The backing is support for the warrant itself. A qualifier limits how strongly the claim is stated, with words such as "probably," "in most cases" or "for most families." The rebuttal names the conditions under which the claim would not hold.

Here is a short example. Claim: the town should add a bus route to the hospital. Grounds: a survey found that many residents without cars miss medical appointments. Warrant: if a public service could prevent missed medical care at reasonable cost, the town should provide it. The warrant is where disagreements often hide. A reader might accept the survey but reject the warrant, perhaps believing that private transport or charities should fill the gap. Spelling out the warrant lets you defend it, or discover that you need a different one.

Qualifiers deserve special praise. Writers sometimes fear that "probably" sounds weak. In fact, a claim stated with honest limits is harder to knock down than one that overreaches, and readers trust a writer who does not claim more than the evidence shows.

Counterarguments and concessions

Every serious argument faces objections, and readers who hold them will be thinking of them as they read. Addressing them is not a sign of weakness. The rule is to take on the strongest version of the opposing case, not a feeble one, because defeating a weak version will not move the people who hold the strong one. Sometimes the honest response is a concession: granting a point the other side gets right, then explaining why your claim still holds or how you would adjust it. "It is true that the route will cost money; the survey suggests it would cost less than the emergency care that missed appointments lead to."

The Rogerian approach

When readers are strongly opposed or a topic is heated, a confrontational structure can backfire. In 1970 the rhetoricians Richard Young, Alton Becker and Kenneth Pike adapted ideas from the psychologist Carl Rogers into an approach now called Rogerian argument. Its first step is to state the opposing view so fairly that its holders would agree with your account of it. Only then does the writer identify common ground and present their own position as a way of meeting shared goals. The approach rests on a simple observation: people are far more willing to consider a new view once they feel their own has been understood.

Worked example: library hours

A resident writes to the local paper. Draft thesis: "Libraries are important." Arguable? Barely. Revised thesis: "Our city should keep the main library open until 9 p.m. on weeknights." Now there is something to defend. Grounds: many working parents and students cannot visit before 6 p.m., when the library now closes. Warrant: a public library should be open when the public can use it. Qualifier: "at least on weeknights during the school year." Counterargument: longer hours cost money in staff time.

Concession and response: the cost is real, so the writer proposes a one-year trial with a count of evening visitors, which would let the city decide on evidence rather than guesswork. Because some readers will care mainly about the budget, the writer opens the paragraph on cost by stating their concern fairly before answering it. The finished letter is not louder than the first draft. It is more precise, more honest about costs and easier to agree with.