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.
Letter 137, written in 395 and addressed to a fellow-student in Alexandria, Herculian, is a farewell to a dear friend, who apparently had to leave the city after Syenesius had loose-tonguedly betrayed a secret. The addressee remained an intimate friend, who also received letters 138, 139, 145, 140, 141, 142, 146, 143, and 144.
This letter is offered in the translation by A. Fitzgerald.
Letter 137: A Difficult Goodbye
 To Herculian
If Homer had told us that it was an advantage to Odysseus in his wanderings that he saw the towns and became acquainted with the mind of many nations,note[Homer, Odyssey 1.3.] and although the people whom he visited were not cultured, but merely Laestrygonians and Cyclopses, how wondrously then would poetry have sung of our voyage, a voyage in which it was granted to you and me to experience marvelous things, the bare recital of which had seem to us incredible!
 We have seen with our eye, we have heard with our ears the ladynote[Hypatia.] who legitimately presides over the mysteries of philosophy. And if human interests join those who share them in a bond of union, so a divine law demands of us who are united in mind, which is the best part of us, to honor each other's qualities.
 For my part, after having rejoiced so much in your bodily presence with me, it seems to me as if I still saw you, although now you are absent from me, for memory furnishes me with the image that your disposition produces within me. The wondrously sweet echo of your sacred words resounds in my ears. If you do not feel all that I feel, you do me wrong indeed; but if you do feel all this, it is simple enough. You are only in that case repaying the debt of friendship.
 Whenever my thoughts go back to our association in the study of philosophy, and to that philosophy at which we have both laboriously toiled, under the influence of reasoning I attribute our meeting to God the ruler.
 For it must needs be from no less than a divine cause that I, Synesius, thus readily disclosed myself and all that is mine to a man with whom I had hardly conversed; I, the least inclined to vulgarize such subjects, whose contact with men is frequent, but whose conversation with them is confined to subjects of general interest, and who hold philosophy to be the most unutterable amongst unutterable things. Now, when the being appeared to whom I betrayed matters that were not to be found out by inquiry until that moment, I had quite forgotten the cunning art of Proteus;note[According to Homer (Odyssey, 4.412ff), an Egyptian god, who could change his shape.] and this was naught else than to live in the midst of men, not as a god, but as a citizen. Since this happened without any forethought on my part, but quite unrehearsed, I account God the prime mover in the unexpected event. Therefore we will beg Him to conduct in a prosperous end what He has begun, and to grant us to study philosophy together if possible, but if not, in any case, to study philosophy.
 I am in the throes of thought, longing to pour over my letter certain arguments that are in my mind, concerning that subject we were discussing, but I shall not do anything of the sort. If God permit me, it may befall you to discuss the matter with us, and with many who have better knowledge! I cannot believe that it is a good thing to confide secrets of this sort to paper, for it is not the business of a letter to hold its peace; its nature is to speak to the first comer.
 Goodbye then, study philosophy, and go on digging up the eye that is buried within us. For an upright life, which I consider the beginning of wisdom, has been enjoined upon us by the wise men of old. The inspired voice says that it is not right for the unpurified to handle that which is pure; but the masses think that uprightness of life does not exist for the end of wisdom, but stands by itself, and is itself the perfection of man, and that the way is not a way merely, but the goal itself at which we must aim. In this view they are mistaken. An unreasoning self-control and an abstinence from eating of meat, have been given to many unreasoning creatures by nature. We do not commend a raven or any other creature that has discovered a natural virtue, because they are devoid of reasoning power. To live according to reason is the end of man. Let us pursue that life; let us ask God to turn our thoughts to divine things, and let us ourselves, as much as is possible for us, gather wisdom from all sides.