Synesius of Cyrene (c.370-c.413) was a Neo-Platonic philosopher who became bishop of Ptolemais in the Cyrenaica. He left behind a small corpus of texts that offer much information about daily life in Late Antiquity, and about the christianization of the Roman world.
Joannes, the addressee of this letter and letters 63 and 2 (all written in 407) was apparently an enemy of Synesius. The letter is offered here in the translation of A. Fitzgerald.
Letter 64: A Warning
 To Joannes
Do not ask great things, for you run two dangers; if successful you wound, and if unsuccessful you are wounded.