Unit 3 · Topic 3.7

3.7 Building a line of reasoning with evidence and commentary

A line of reasoning is the chain of claims that leads your reader, step by step, to your thesis. Each body paragraph needs specific evidence and commentary that explains how that evidence supports its claim and how the claim supports the thesis. This is where most essay points are won or lost.

Key terms

line of reasoning
evidence
commentary
topic sentence
unity

Line of reasoning

A line of reasoning is the chain of claims, in a logical order, that leads your reader to accept your thesis. Think of your thesis as a destination and your body paragraph claims as the route. Each claim should move the argument forward, not just add another example of the same thing.

Your commentary is what shows the route. It explains how each piece of evidence supports its claim and how each claim connects to the thesis. Without commentary, a reader sees quotations but no argument.

Using evidence on purpose

Evidence works when your commentary explains its link to the claim. You have enough when there's enough of it, and it's specific enough, to support every step of your reasoning. One great quotation per claim, well explained, often beats three weak ones.

Choose each piece of evidence for a reason. Evidence can:

show an idea in action (an example of a trait or pattern);
clarify a point that might be unclear;
connect two parts of the work;
intensify a point by showing it at its strongest;
limit or qualify a point, showing where it stops being true.

Two ways in

You can start with evidence and let an interpretation grow from it, or start with an interpretation and go find evidence. Good writers move back and forth. If the evidence pushes back against your thesis, adjust the thesis. That isn't failure; it's how sharp arguments form.

Clean writing helps your argument

Grammar and mechanics matter because they let your reader follow your thinking. The essays are scored for their ideas, not their polish, and small errors are forgiven. But the scoring guidelines say that errors serious enough to interfere with communication keep a response from earning the top score in the evidence-and-commentary row.

Topic sentences carry the reasoning

Each body paragraph should open with a claim that moves your argument forward, not with a quotation or a plot fact. Compare "Ethan goes to the church dance to walk Mattie home" (plot) with "Ethan's first scene with Mattie, in which he watches her through a window instead of going in, shows that he would rather watch his life than act in it" (claim). The second sentence tells the reader what the paragraph will prove and how it connects to the thesis.

Worked examples

Try each one yourself first, then open the solution.

Example 1
Planning and writing one body paragraph
Use the thesis from 3.6: "Although Ethan Frome's devotion to his family looks like a noble sense of duty, Wharton suggests that his loyalty is also a kind of paralysis." In the novel's frame, the narrator remarks that the broken-down Ethan looks "as if he was dead and in hell now!" A local man, Harmon Gow, replies: "Guess he's been in Starkfield too many winters. Most of the smart ones get away." When the narrator asks "Why didn't he?", Harmon answers: "Somebody had to stay and care for the folks. There warn't ever anybody but Ethan. Fust his father—then his mother—then his wife." Plan a line of reasoning and write the first body paragraph.
Show the solutionHide the solution
1. Step 1: Plan the route. Claim 1: the town's view frames Ethan's staying as duty that wore him down. Claim 2: his own choices in the story show he avoids decisions. Claim 3: the ending shows his duty has become a trap he can't escape.
2. Step 2: For claim 1, choose evidence. Harmon's list, "Fust his father—then his mother—then his wife," shows obligation piling up; "too many winters" links staying to slow damage.
3. Step 3: Plan the commentary. Explain how the list's dashes make the duties feel endless, and how "Most of the smart ones get away" hints that staying was partly a failure to act.
4. Step 4: End by linking back to the thesis.
Answer: Model body paragraph: From the start, the people of Starkfield describe Ethan's loyalty as something that happened to him rather than something he chose. Harmon Gow explains that "Somebody had to stay and care for the folks," and his list, "Fust his father—then his mother—then his wife," runs on with dashes, as if each duty simply replaced the last without a break. The sentence makes obligation feel endless. Yet Harmon's other remark complicates the picture: Ethan has "been in Starkfield too many winters," while "Most of the smart ones get away." Leaving, in this town, is something people actively do, so staying begins to look less like noble sacrifice and more like a failure to act. Before Ethan's story even starts, Wharton plants the idea that his duty and his paralysis are hard to tell apart.

Common mistakes

Making each body paragraph a separate observation with no link to the next. Ask how each claim moves the argument forward.
Letting quotations stand alone. Each one needs commentary that names specific words and explains them.
Repeating the same point with new examples. Each claim should add something new.
Sticking to a thesis the evidence doesn't support. Adjust it.

On the exam

The 4-point evidence-and-commentary row rewards a clear line of reasoning built from specific evidence that's consistently explained. That's the difference between a 2 and a 4 in that row.
Before writing, take a minute to jot your thesis and two or three claims. A quick plan keeps your reasoning connected under time pressure.

Connected topics

Videos

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Check yourself

4 questions on 3.7 Building a line of reasoning with evidence and commentary. Pick an answer to see if you got it, and why.

COUNTY ATTORNEY: (looking around) I guess we'll go upstairs first—and then out to the barn and around there, (to the SHERIFF) You're convinced that there was nothing important here—nothing that would point to any motive.

SHERIFF: Nothing here but kitchen things.

(The COUNTY ATTORNEY, after again looking around the kitchen, opens the door of a cupboard closet. He gets up on a chair and looks on a shelf. Pulls his hand away, sticky.)

COUNTY ATTORNEY: Here's a nice mess.

(The women draw nearer.)

MRS PETERS: (to the other woman) Oh, her fruit; it did freeze, (to the LAWYER) She worried about that when it turned so cold. She said the fire'd go out and her jars would break.

SHERIFF: Well, can you beat the women! Held for murder and worryin' about her preserves.

COUNTY ATTORNEY: I guess before we're through she may have something more serious than preserves to worry about.

HALE: Well, women are used to worrying over trifles.

(The two women move a little closer together.)

COUNTY ATTORNEY: (with the gallantry of a young politician) And yet, for all their worries, what would we do without the ladies? (the women do not unbend. He goes to the sink, takes a dipperful of water from the pail and pouring it into a basin, washes his hands. Starts to wipe them on the roller-towel, turns it for a cleaner place) Dirty towels! (kicks his foot against the pans under the sink) Not much of a housekeeper, would you say, ladies?

MRS HALE: (stiffly) There's a great deal of work to be done on a farm.

COUNTY ATTORNEY: To be sure. And yet (with a little bow to her) I know there are some Dickson county farmhouses which do not have such roller towels. (He gives it a pull to expose its length again.)

MRS HALE: Those towels get dirty awful quick. Men's hands aren't always as clean as they might be.

COUNTY ATTORNEY: Ah, loyal to your sex, I see. But you and Mrs Wright were neighbors. I suppose you were friends, too.

MRS HALE: (shaking her head) I've not seen much of her of late years. I've not been in this house—it's more than a year.

COUNTY ATTORNEY: And why was that? You didn't like her?

MRS HALE: I liked her all well enough. Farmers' wives have their hands full, Mr Henderson. And then—

COUNTY ATTORNEY: Yes—?

MRS HALE: (looking about) It never seemed a very cheerful place.

COUNTY ATTORNEY: No—it's not cheerful. I shouldn't say she had the homemaking instinct.

MRS HALE: Well, I don't know as Wright had, either.

COUNTY ATTORNEY: You mean that they didn't get on very well?

MRS HALE: No, I don't mean anything. But I don't think a place'd be any cheerfuller for John Wright's being in it.

COUNTY ATTORNEY: I'd like to talk more of that a little later. I want to get the lay of things upstairs now. (He goes to the left, where three steps lead to a stair door.)

SHERIFF: I suppose anything Mrs Peters does'll be all right. She was to take in some clothes for her, you know, and a few little things. We left in such a hurry yesterday.

COUNTY ATTORNEY: Yes, but I would like to see what you take, Mrs Peters, and keep an eye out for anything that might be of use to us.

MRS PETERS: Yes, Mr Henderson.

(The women listen to the men's steps on the stairs, then look about the kitchen.)

MRS HALE: I'd hate to have men coming into my kitchen, snooping around and criticising.

(She arranges the pans under sink which the LAWYER had shoved out of place.)

MRS PETERS: Of course it's no more than their duty.

Susan Glaspell, Trifles (first performed 1916), from Plays (1920)

Question 1 of 4

A student argues that the play shows a divide between how the men and the women see Mrs. Wright's life. Which pair of details from the passage would best support this claim?

I had the story, bit by bit, from various people, and, as generally happens in such cases, each time it was a different story.

If you know Starkfield, Massachusetts, you know the post-office. If you know the post-office you must have seen Ethan Frome drive up to it, drop the reins on his hollow-backed bay and drag himself across the brick pavement to the white colonnade; and you must have asked who he was.

It was there that, several years ago, I saw him for the first time; and the sight pulled me up sharp. Even then he was the most striking figure in Starkfield, though he was but the ruin of a man. It was not so much his great height that marked him, for the “natives” were easily singled out by their lank longitude from the stockier foreign breed: it was the careless powerful look he had, in spite of a lameness checking each step like the jerk of a chain. There was something bleak and unapproachable in his face, and he was so stiffened and grizzled that I took him for an old man and was surprised to hear that he was not more than fifty-two. I had this from Harmon Gow, who had driven the stage from Bettsbridge to Starkfield in pre-trolley days and knew the chronicle of all the families on his line.

“He’s looked that way ever since he had his smash-up; and that’s twenty-four years ago come next February,” Harmon threw out between reminiscent pauses.

The “smash-up” it was—I gathered from the same informant—which, besides drawing the red gash across Ethan Frome’s forehead, had so shortened and warped his right side that it cost him a visible effort to take the few steps from his buggy to the post-office window. He used to drive in from his farm every day at about noon, and as that was my own hour for fetching my mail I often passed him in the porch or stood beside him while we waited on the motions of the distributing hand behind the grating. I noticed that, though he came so punctually, he seldom received anything but a copy of the Bettsbridge Eagle, which he put without a glance into his sagging pocket. At intervals, however, the post-master would hand him an envelope addressed to Mrs. Zenobia—or Mrs. Zeena—Frome, and usually bearing conspicuously in the upper left-hand corner the address of some manufacturer of patent medicine and the name of his specific. These documents my neighbour would also pocket without a glance, as if too much used to them to wonder at their number and variety, and would then turn away with a silent nod to the post-master.

“It was a pretty bad smash-up?” I questioned Harmon, looking after Frome’s retreating figure, and thinking how gallantly his lean brown head, with its shock of light hair, must have sat on his strong shoulders before they were bent out of shape.

“Wust kind,” my informant assented. “More’n enough to kill most men. But the Fromes are tough. Ethan’ll likely touch a hundred.”

“Good God!” I exclaimed. At the moment Ethan Frome, after climbing to his seat, had leaned over to assure himself of the security of a wooden box—also with a druggist’s label on it—which he had placed in the back of the buggy, and I saw his face as it probably looked when he thought himself alone. “That man touch a hundred? He looks as if he was dead and in hell now!”

Harmon drew a slab of tobacco from his pocket, cut off a wedge and pressed it into the leather pouch of his cheek. “Guess he’s been in Starkfield too many winters. Most of the smart ones get away.”

“Why didn’t he?”

“Somebody had to stay and care for the folks. There warn’t ever anybody but Ethan. Fust his father—then his mother—then his wife.”

“And then the smash-up?”

Harmon chuckled sardonically. “That’s so. He had to stay then.”

“I see. And since then they’ve had to care for him?”

Harmon thoughtfully passed his tobacco to the other cheek. “Oh, as to that: I guess it’s always Ethan done the caring.”

Though Harmon Gow developed the tale as far as his mental and moral reach permitted there were perceptible gaps between his facts, and I had the sense that the deeper meaning of the story was in the gaps. But one phrase stuck in my memory and served as the nucleus about which I grouped my subsequent inferences: “Guess he’s been in Starkfield too many winters.”

Edith Wharton, Ethan Frome (1911)

Question 2 of 4

A student writes: “Wharton shows that Ethan's suffering is not only physical. When the narrator glimpses Ethan's face ‘as it probably looked when he thought himself alone,’ he exclaims that Ethan looks ‘dead and in hell.’” Which sentence would best continue the paragraph with commentary?

It was a random shot, and yet the reporter’s instinct was right. Gatsby’s notoriety, spread about by the hundreds who had accepted his hospitality and so become authorities upon his past, had increased all summer until he fell just short of being news. Contemporary legends such as the “underground pipeline to Canada” attached themselves to him, and there was one persistent story that he didn’t live in a house at all, but in a boat that looked like a house and was moved secretly up and down the Long Island shore. Just why these inventions were a source of satisfaction to James Gatz of North Dakota, isn’t easy to say.

James Gatz—that was really, or at least legally, his name. He had changed it at the age of seventeen and at the specific moment that witnessed the beginning of his career—when he saw Dan Cody’s yacht drop anchor over the most insidious flat on Lake Superior. It was James Gatz who had been loafing along the beach that afternoon in a torn green jersey and a pair of canvas pants, but it was already Jay Gatsby who borrowed a rowboat, pulled out to the Tuolomee, and informed Cody that a wind might catch him and break him up in half an hour.

I suppose he’d had the name ready for a long time, even then. His parents were shiftless and unsuccessful farm people—his imagination had never really accepted them as his parents at all. The truth was that Jay Gatsby of West Egg, Long Island, sprang from his Platonic conception of himself. He was a son of God—a phrase which, if it means anything, means just that—and he must be about His Father’s business, the service of a vast, vulgar, and meretricious beauty. So he invented just the sort of Jay Gatsby that a seventeen-year-old boy would be likely to invent, and to this conception he was faithful to the end.

But his heart was in a constant, turbulent riot. The most grotesque and fantastic conceits haunted him in his bed at night. A universe of ineffable gaudiness spun itself out in his brain while the clock ticked on the washstand and the moon soaked with wet light his tangled clothes upon the floor. Each night he added to the pattern of his fancies until drowsiness closed down upon some vivid scene with an oblivious embrace. For a while these reveries provided an outlet for his imagination; they were a satisfactory hint of the unreality of reality, a promise that the rock of the world was founded securely on a fairy’s wing.

An instinct toward his future glory had led him, some months before, to the small Lutheran College of St. Olaf’s in southern Minnesota. He stayed there two weeks, dismayed at its ferocious indifference to the drums of his destiny, to destiny itself, and despising the janitor’s work with which he was to pay his way through. Then he drifted back to Lake Superior, and he was still searching for something to do on the day that Dan Cody’s yacht dropped anchor in the shallows alongshore.

F. Scott Fitzgerald, The Great Gatsby (1925), Chapter VI

Question 3 of 4

Which detail from the passage best supports the claim that Gatsby's dreams made him scornful of ordinary work?

How all occasions do inform against me,

And spur my dull revenge. What is a man

If his chief good and market of his time

Be but to sleep and feed? A beast, no more.

Sure he that made us with such large discourse,

Looking before and after, gave us not

That capability and godlike reason

To fust in us unus’d. Now whether it be

Bestial oblivion, or some craven scruple

Of thinking too precisely on th’event,—

A thought which, quarter’d, hath but one part wisdom

And ever three parts coward,—I do not know

Why yet I live to say this thing’s to do,

Sith I have cause, and will, and strength, and means

To do’t. Examples gross as earth exhort me,

Witness this army of such mass and charge,

Led by a delicate and tender prince,

Whose spirit, with divine ambition puff’d,

Makes mouths at the invisible event,

Exposing what is mortal and unsure

To all that fortune, death, and danger dare,

Even for an eggshell. Rightly to be great

Is not to stir without great argument,

But greatly to find quarrel in a straw

When honour’s at the stake. How stand I then,

That have a father kill’d, a mother stain’d,

Excitements of my reason and my blood,

And let all sleep, while to my shame I see

The imminent death of twenty thousand men

That, for a fantasy and trick of fame,

Go to their graves like beds, fight for a plot

Whereon the numbers cannot try the cause,

Which is not tomb enough and continent

To hide the slain? O, from this time forth,

My thoughts be bloody or be nothing worth.

William Shakespeare, Hamlet (c. 1600), Act IV, Scene iv. “fust”: grow moldy. “Sith”: since. “Makes mouths at the invisible event”: mocks the unknown outcome. “Excitements”: urgings. “continent”: container.

Question 4 of 4

A student plans an essay arguing that the soliloquy shows a mind that argues itself toward action without ever reaching it. Which plan for the body paragraphs would best develop this line of reasoning?

0 of 4 answered