No painting by Diego Velázquez has sparked more questions than Temptation of St. Thomas, a work whose very existence is a matter of scholarly debate. While several 17th-century inventories mention a Velázquez canvas on this subject, no universally accepted painting survives today, and its medium remains undocumented.

The painting is known primarily through written records and copies attributed to followers, leaving art historians to piece together its appearance and significance from fragments and descriptions. At the heart of the story is St. Thomas Aquinas, the Dominican scholar, confronted by a vision of temptation in his cell. Velázquez, according to surviving descriptions, chose the moment when a demure angel intervenes, driving away a provocatively dressed woman—sent by Thomas's own family to test his resolve.

The saint, kneeling in prayer, is said to be illuminated by a shaft of light, symbolizing divine protection, while the discarded chain at his feet alludes to his subsequent chastity. Unlike Caravaggio’s turbulent Temptation of Saint Matthew, Velázquez’s approach reportedly emphasized restraint and psychological tension rather than overt drama. The fate of Temptation of St. Thomas remains uncertain.

If it was indeed painted by Velázquez around 1632, it would have fallen within his early Madrid years, a period when he was exploring religious themes for royal and ecclesiastical clients. Some scholars suggest the painting was commissioned for a Dominican institution, but no definitive provenance has been traced. Today, the work is counted among the lost or unidentified paintings of Velázquez, its legend living on in catalogues and scholarly debate, a tantalizing ghost in the artist’s celebrated catalogue.