C.S. Lewis’s childhood dog was named Jacksie, and its death influenced his choice of nickname.
In 1908, when Lewis was nine years old, his dog Jacksie was killed by a car. Lewis subsequently insisted on being called “Jacksie,” later shortened to “Jack.” The nickname remained with him for the rest of his life, and friends and colleagues generally knew him as Jack rather than Clive.
The episode is important because it explains the familiar name used in biographies, letters, and reminiscences. “C.S. Lewis” was his public authorial name, while “Jack” was the personal name used by people who knew him. His brother Warren also used “Warnie” as a longstanding nickname.
Lewis’s early life included several experiences of grief, including the death of his mother when he was nine. Those events influenced his later reflections on loss, imagination, and religious belief, although no single episode explains all of his intellectual development.