De Clementia (frequently translated as On Mercy in English) is a two volume (incomplete) hortatory essay written in AD 55–56 by Seneca the Younger, a Roman Stoic philosopher, to the emperor Nero in the first five years of his reign.

[2] From Seneca's remarks, it would appear that it was written after Nero had turned eighteen, which would place it after the murder of his rival Britannicus in AD 55.

[2] It may therefore have been written partly as an apology, perhaps as a means of assuring the Roman nobility that the murder would be the end, not the beginning of bloodshed.

A survey of history is made in the first volume to select different rulers to point out as examples, including Dionysius of Syracuse and Sulla being used as cautionary tales and young Augustus as the exemplar.

Thus, clemency, not pity or unmotivated generosity, is the reasonable approach which guarantees the consent and devotion of the emperor's subjects and provides the state's security.

[8] The text has come down to us together with De Beneficiis in one of the earliest surviving Senecan manuscripts, as part of the 8th century Codex Nazarianus (Vat.

[8] Although always regarded as a minor work of Seneca's, it received one significant appraisal in 1532 when John Calvin published his commentary on it.

[8] Shortly after finishing his legal studies, a young John Calvin wrote his first book, a commentary on De Clementia.

The lack of a dedication to him, mention of him, and gross error that would have been made comparing Francis with Nero all lead to the theory's disuse.