(phr.) to urge someone to reconsider an unfavourable decision

To appeal from Philip drunk to Philip sober is a sixteenth century turn of phrase meaning ‘to urge someone to reconsider an unfavourable decision’.

The Philip in question here is Philip of Macedon, the father of Alexander the Great. According to an anecdote told by the Roman historian Valerius Maximus, Philip was once approached by a Macedonian noblewoman to seek a ruling on some apparent slight or legal matter she had found problematic. Unfortunately for her, the king at the time was in a drunken, petulant, and fairly unsympathetic mood, and ultimately dismissed her case without hearing it out fully.

Disappointed, the woman said that she would appeal the king’s judgment, and when Philip angrily asked to whom she intended to direct her appeal, she explained simply, “to Philip sober”—rather than, it was implied, “Philip drunk”. (Legend has it that she subsequently won her case with the king’s pardon, and was happily vindicated.)

This tale gave rise to the expression above and first found its way into more widespread use in English in the early 1500s. It has been used—albeit rarely—ever since to describe any attempt to have someone reconsider a snap or ill-advised judgment at a later date.