 Douglas MacDowell believes that this is authentically Philip's letter.Fifty-five passages bearing the collective title "prooimia" (or "prooimia dēmēgorika") — "(demegoric) prologues" or "preambles" — are extant.These were openings of Demosthenes' speeches, collected by Callimachus for the Library of Alexandria, and preserved in several of the manuscripts that contain Demosthenes' speeches.