The narrative begins before the protagonist's birth, detailing the unfortunate circumstances of his conception and the pedantic theories of his father, Walter Shandy. Walter holds firm beliefs regarding the influence of Christian names, the mechanics of the mind, and the proper methods of childbirth, often clashing with his brother, Uncle Toby. Uncle Toby, wounded at the siege of Namur, remains absorbed in military fortifications and miniature battle reconstructions on his bowling green with Corporal Trim. Throughout these domestic scenes, the author continually interrupts the main plot with philosophical reflections, satirical essays, and digressions on time and existence.
The arrival of Dr. Slop, the man-midwife, introduces further comedic complications, culminating in chaotic attempts to assist Mrs. Shandy during labor. Interwoven throughout the text are sermons, curses, and pointed commentary on the nature of human understanding and narrative itself. The text famously explores how human thoughts and associations dictate reality, presenting a richly textured tapestry of English humor and experimental form.