Exhalation

Chiang's second collection contains nine stories, each built around a specific conceptual premise worked through rigorously. Chiang publishes rarely and the stories are unusually careful about their own logic.

The Merchant and the Alchemist's Gate uses a time travel mechanism in which the past cannot be changed, only understood, framed as a story in the style of the Thousand and One Nights. The title story describes a mechanical being dissecting its own brain to discover how memory works and what is actually running down in its universe. The Lifecycle of Software Objects, a novella, follows people raising artificial intelligences over years and addresses what obligations arise when a created being develops through experience rather than being programmed. Anxiety Is the Dizziness of Freedom uses a device that opens communication with branches of a quantum multiverse and examines what happens to moral responsibility when every choice was also made otherwise. Omphalos concerns a scientist in a world with clear evidence of creation who discovers evidence that humanity was not its purpose.

The recurring subject is free will, determinism and how a person should act if their choices were determined. Chiang's position, stated in the story notes, is that the question of whether free will exists matters less than whether people behave as though it does.

The stories are more interested in ideas than in character, and readers wanting emotional depth will find the earlier collection stronger in that respect. The story notes at the end explain the premise of each, which some readers find diminishes them. The artificial intelligence novella is the most directly relevant to technology readers and is more thoughtful about the subject than most non-fiction on it.