As Mrs. Shandy begins to go into labor, Walter and Uncle Toby are sitting in the parlor. Walter wonders what all the noise is upstairs, and Uncle Toby says "I think — ." Tristram interrupts to say that before he can let him finish his sentence, it is appropriate to outline Uncle Toby's character. Writing on "this very rainy day, March 26, 1759, and betwixt the hours of nine and ten in the morning," he recalls that none of the Shandy females had any character except his great-aunt Dinah. Then Uncle Toby's character-drawing goes on. Toby was a most virtuous, extremely modest man; he acquired his modesty from "a blow from a stone . . . at the siege of Namur, which struck full" upon his groin — a long and interesting story. "'Tis for an episode hereafter." In the interim, suffice it to say that whenever Walter told the story of their Aunt Dinah, who "was married and got with child by the coachman," Toby's sense of modesty was outraged. Walter persisted in expounding his theory of their family: "What is the character of a family to an hypothesis?" he would say, and because it was useless to argue with him, Toby would whistle "Lillabullero," a favorite song. After outlining the classical types of argument, Tristram suggests that this kind of argument be named the "Argumentum Fistulatorium" — argument by whistling.
Tristram discusses his digressions, noting that in his latest one, "there is a masterstroke of digressive skill": as he was about to tell of Toby's character, he thought of his Aunt Dinah and the coachman, but the reader will "perceive that the drawing of my uncle Toby's character went on gently all the time . . . so that you are much better acquainted" with him now. Thus, he concludes, "my work is digressive, and it is progressive too, — and at the same time."
Digressions are the sunshine, the life, and the soul of reading, says Tristram: "Take them out of this book for instance, — you might as well take the book along with them." The author's problem is serious: if he digresses, the whole book stands still, "and if be goes on with his main work, — then there is an end of his digression." But he has constructed the book so that, like one wheel within another, the "digressive and progressive movements" go on together, and "it shall be kept a-going these forty years."
If people had windows in their breast, we could tell at a glance what someone was like. But they don't, and we are liable to make many mistakes about their character. To avoid these errors, Tristram says, "I will draw my uncle Toby's character from his HOBBY-HORSE." It was an unusual hobby-horse, but before telling what it is, Tristram must first explain how Toby came to acquire it.
After being wounded in his groin, Toby was confined to bed for four years; since there was so much brotherly love between them, Walter took him into his house in London. Talking about the circumstances of his wound gave him much relief, so Walter gladly listened to his stories of the siege in which he was hurt. Something came up, however, that threatened to retard his cure. What it is, Tristram will tell about in the next book; the reader can't possibly guess.
Although we aren't told it quite yet, Tristram actually has brought his mother to the point of bearing him. But it is to be put off still. Uncle Toby's character is the next item on the author's agenda, and he launches into it by interrupting Toby's sentence. (That sentence will be completed 10 chapters later, in Book 2, Chapter 6.)
Again we have a reminder that the writer has his own thoughts — it is March 26, 1759 — and one of his thoughts is about his Aunt Dinah, a family scandal. The story of Aunt Dinah and the coachman serves to show the great difference between the brothers, Walter and Toby, and it shows Toby's extreme modesty.
Tristram analyzes his "digressive-progressive" technique, and his argument in its favor is clear and convincing: the digressions are really digressions, but the story goes on because, as he says, we continue to know more about Uncle Toby's character even though Tristram is ostensibly talking about something else.
His discussion of the way he has solved the problem is a piece of learned jargon; he is satirizing techniques, rules, and mechanical approaches to writing. But it is nonetheless true; his claim that the digressions work in much more closely than they seem to turns out to be so. The architecture of the whole labyrinth is very careful. The supposedly casual attitude he has to his forward development — he'll be writing the book for forty years — is just a typical Shandean joke; he knows where he's going, and he has a sense of proportion.
The character drawing goes on. The wound in Toby's groin starts his hobby, although what it is we don't know yet. An exposé of Toby's hobby will provide all the clues we need in order to understand his character, but the author must first give more background about the origin of the hobby. But before that, he must tell about something before that — in the next book.