If you were fascinated by Peter Sinclair’s struggle to define what is real and what is a construct of his mind in The Affirmation, you’ll love The Raw Shark Texts by Steven Hall. This novel also features a protagonist whose perceptions are deeply unreliable, blending psychological suspense with metafictional puzzles. Like Priest’s work, Hall’s story keeps you questioning the nature of reality, memory, and identity all the way to the end.

If you enjoyed the way The Affirmation toys with the boundaries between author and narrative, you’ll be enthralled by Calvino’s If on a winter's night a traveler. This book constantly breaks the fourth wall, inviting you to become a character in its labyrinthine plot. Like Priest, Calvino weaves fiction and reality together, leaving you marveling at the artifice and construction of storytelling itself.

If the non-linear, mind-bending structure of The Affirmation intrigued you, Slaughterhouse-Five will be a perfect follow-up. Follow Billy Pilgrim as he becomes 'unstuck in time,' experiencing life, death, and alien abduction in an order that defies chronology. Vonnegut’s classic similarly blurs the lines between what is remembered, imagined, and truly experienced.

If you were drawn to the philosophical undertones of The Affirmation—its questions about the nature of reality, consciousness, and self—then Solaris by Stanislaw Lem is a must-read. In this novel, psychologist Kris Kelvin confronts a sentient ocean that manifests his deepest fears and desires, forcing him to grapple with the limits of human understanding and the slipperiness of truth.

If you appreciated the psychological complexity and shifting identities in The Affirmation, Foe by J. M. Coetzee will resonate with you. This novel reimagines the story of Robinson Crusoe through the eyes of a new narrator, Susan Barton, exploring the construction of identity, truth, and authorship with the same haunting ambiguity and introspection that made Priest's novel so memorable.