Corporal Trim enters with the copy of Stevinus' book, which Toby had sent him after. Toby tells the corporal to take the book back home, but first Walter jocularly asks him to look through the book for a "sailing chariot." As Trim shakes the book, out fall some papers that turn out to be a sermon. Walter asks Trim to read some of it, and he is delighted to have the chance to perform. Walter asks Dr. Slop if he objects; he doesn't, saying "it may be a composition of a divine of our church" (the Catholic church). Trim says that since it is on Conscience, "'Tis wrote upon neither side."
Tristram describes in fine detail the corporal's stance, the position of his legs, the angles of his body; he has the posture of an expert orator.
The way Trim reads the first sentence of the sermon provokes Dr. Slop into an argument with the others: "For we trust we have a good Conscience." Dr. Slop defends the Inquisition, which would persecute anyone who took exception to the text of the Bible, and Trim tearfully speaks about his brother who has been imprisoned by the Inquisition for fourteen years.
Trim continues reading, with comments by both Dr. Slop and Walter on the meaning of the sermon. It turns out to have an anti-Catholic bias, and Dr. Slop falls asleep in the middle. Toward the end, in a description of the practices of the Inquisition, Trim takes the sermon literally as an account of what is happening to his brother Tom, and he cannot read without commenting at each line. Walter finishes the reading.
The sermon, they decide, was written by Parson Yorick, who had borrowed Toby's copy of Stevinus and left the sermon between the pages.
Obadiah returns with Dr. Slop's bag of instruments, and Walter informs Dr. Slop that he is to be merely an auxiliary; unless the midwife sends for him, he is to remain downstairs. Dr. Slop says that there have been such improvements in obstetrical knowledge, especially in "the safe and expeditious extraction of the foetus," that he wonders "how the world has — " and he is interrupted by Uncle Toby, who says, "I wish . . . you had seen what prodigious armies we had in Flanders."
