Body Paragraphs and the Line of Reasoning: Study Guide (English Language 5.1)

From thesis to paragraphs

A thesis makes a claim that cannot be proved in a single sentence. The body of the argument proves it in steps, and each step is a body paragraph. The framework sets out what these paragraphs do: they make claims, support them with evidence and provide commentary that explains how the paragraph contributes to the reasoning of the argument.

Three parts, then, with one job each:

Part	What it is	What it does for the reader
Claim	A statement that needs support, usually the opening or topic sentence	Tells the reader what the paragraph will prove and links it to the thesis
Evidence	Facts, examples, data, quotations, anecdotes, authorities	Gives the reader something to check
Commentary	The writer’s explanation of what the evidence shows and how it advances the argument	Does the thinking so that the reader does not have to

The order is not rigid. A writer may place commentary between two pieces of evidence, or open with evidence and reveal the claim at the end. What matters is that all the jobs are done and the reader can tell which is which.

Commentary: where the thinking happens

The most common weakness in body paragraphs is evidence with no commentary. A paragraph that says “Here is a fact. Here is another fact” leaves the reader to decide what they mean. Commentary does that work. Good commentary can:

• Explain how the evidence supports the claim (“This matters because…”).
• Interpret the evidence (“The word ‘only’ suggests that…”).
• Connect the evidence to the thesis (“This is one of the ways the policy fails the students it was meant to help”).
• Qualify the evidence (“This suggests, though it does not prove…”).

A reliable test: remove the evidence and see whether the commentary still tells the reader something. If it only says “This shows that the claim is true,” it is not commentary; it is a gesture.

Line of reasoning

A line of reasoning is the progression of claims by which a writer gets from a starting point to the thesis. Each body paragraph is one step, and each step supports the next. Think of a line of stepping stones across a stream: if one is missing or out of place, the reader cannot cross.

In reading, you describe a line of reasoning by summarising the claims in order and saying how they connect. For example: “First the writer shows that the problem is real, then that the usual solution has failed, and finally that a new approach would succeed.” You then judge whether it supports the thesis: does each step lead to the claim, or is there a gap?

In writing, you develop a line of reasoning by choosing a claim for each paragraph, putting the claims in an order that a reader can follow, and using commentary to show how each paragraph moves the argument along.

Weak and strong body paragraphs side by side

Suppose the thesis is: School gardens should be funded because they teach patience, attention and responsibility. The body paragraph on patience might read:

Weak (Marlbridge example):

School gardens are good for students. At Ashgrove Primary, children plant beans in April and the first pods are ready after eleven weeks. Gardens are used in many schools. Students also learn about plants. This shows that gardens are useful.

Strong (Marlbridge example):

School gardens teach patience by making students wait for a result they can see. At Ashgrove Primary, children plant beans in April and must wait eleven weeks for the first pods. During that wait, teachers report, they ask why the leaves yellow in a dry week and when lunch will taste different. These questions show a garden doing what a worksheet cannot: attaching a child’s attention to a process that cannot be hurried. A school that values patience should therefore value the plot of earth where students learn that some results cannot be rushed.

Feature	Weak	Strong
Claim	“Good for students” (vague, not tied to thesis)	“Teach patience” (a specific step in the thesis)
Evidence	Three loosely related statements	One specific case with a detail the reader can check
Commentary	“This shows that gardens are useful” (empty)	Explains what the questions reveal and what a garden does that a worksheet cannot
Link	None	Returns to the value of patience, the first term of the thesis

Worked example 1: adding commentary to a bare paragraph

Draft paragraph (Marlbridge example). The thesis is A town should close its high street to cars on Saturdays because the closure helps shops, residents and the environment. The writer’s first body paragraph says:

Closing the high street helps shops. When a similar street was closed in a neighbouring town, shop takings rose by 12% on Saturdays. Café owners also reported more customers.

Step 1: Identify the parts. Claim: closing helps shops. Evidence: the 12% rise and the café owners’ reports. Commentary: none. The reader has been given a claim and two facts but not told why the facts prove the claim.

Step 2: Ask what the evidence shows. A 12% rise on closure days suggests that more people stop at the shops when cars are absent. The café owners’ reports suggest the effect reaches shops that depend on lingering customers.

Step 3: Consider the likely objection. A sceptic might say: perhaps Saturday would have been busier anyway. A strong paragraph either addresses this or frames the claim with care.

Step 4: Write the commentary.

The rise matters because it suggests the closure changed how people use the street: with no cars to dodge, shoppers stop, linger and spend. The café owners’ reports point the same way, since a café depends on customers who stay. Although one town’s experience cannot prove the same result here, it gives the council a reason to try the closure on a trial basis, which is itself a modest step toward the larger claim that the street works better for people than for traffic.

Step 5: Link to the thesis. The final clause ties the paragraph to the thesis (“works better for people than for traffic”).

Step 6: Check. Claim (helps shops), evidence (12% and cafés), commentary (explains meaning, qualifies, links). Each job is done.

Worked example 2: describing a line of reasoning in a text

Read this short argument (Marlbridge passage).

Paragraph 1. Most people believe that the best way to learn a poem is to memorise it, and few teachers question the habit. But memorising by repetition produces a poem that can be recited and not understood.

Paragraph 2. What helps instead is paraphrase. A student who must say each line in her own words is forced to decide what the line means, and the decisions she makes are the beginning of interpretation.

Paragraph 3. Memory still has a role, but a later one. Once a poem is understood, remembering it costs less effort and lasts longer, because every line is attached to a meaning.

Step 1: Summarise each paragraph’s claim. (1) Memorising by repetition produces recitation without understanding. (2) Paraphrasing forces interpretation. (3) Memory has a role after understanding.

Step 2: Describe the line of reasoning. The writer first challenges a common belief, then proposes an alternative method, and finally reconciles the original view by giving it a new, later place.

Step 3: Judge whether it supports the thesis. The thesis is implied in the opening: memorisation by repetition is a poor way to learn a poem. Paragraph 1 supports it directly. Paragraph 2 offers a better method, which supports the thesis indirectly by showing a superior alternative. Paragraph 3 qualifies the thesis so that it does not seem extreme. The sequence is therefore logical.

Step 4: Write the analysis sentence. The writer moves from challenging a common practice, to offering paraphrase as a better method, to reassigning memory a later role, so that the argument seems balanced and the final position (understand first, then remember) is easy to accept.

Common misconceptions

• “Evidence speaks for itself.” It does not. The writer must explain what it shows.
• “Commentary means summarising the evidence.” Summary repeats; commentary interprets and connects.
• “Every paragraph needs the same shape.” The elements must be present, but their order and proportion can vary.
• “The line of reasoning is the same as the order of the topics.” A list of topics is not a line of reasoning; the claims must connect.
• “Longer paragraphs show more thought.” A paragraph that sprawls over two ideas weakens both. One main claim per paragraph is a good rule.
• “The last sentence of each paragraph should restate the topic sentence.” It should carry the argument forward, not just repeat.

Where this leads

Once the paragraphs have their parts, a reader must feel them hold together. Topic 5.2 looks at unity and coherence. To see how thesis previews shape body paragraphs, go back to Topic 4.3. Check your learning with the practice questions, the revision notes and the checklist.