Although The Egyptian Tale looks like a retelling of a part of the myth of Isis and Osiris, it is obvious that the two brothers Osiris and Typho represent good and bad government. The story, however, is not just a myth, because the man called Osiris can be identified as Aurelian, praetorian prefect of the Eastern Empire during the reign of Arcadius (r.395-408), and one of Synesius' benefactors. The other people in this ancient roman à clef, however, are less easy to identify, but an attempt is made here.
Synesius, On Providence 2.5
[2.5.1]  We may safely venture to say as much as this about Osiris;note[Aurelian.] but beyond this let only words of good augury be spoken, says one who cautiously employs sacred language. As to those things which lie far away, it would be part of a foolhardy mind and tongue to reveal them, and let them be kept in holy silence untouched by written words, lest one should
Cast an eye on anything not permitted,note[Quote from an unknown poet.]
[2.5.2] for he who reveals, as he who sees, such things incurs the wrath of the divine nature. Boeotian legends tear to pieces those who intrude and spy upon the secret rites of Dionysus. Ignorance in the case of initiations is sanctity. On this account the night is entrusted with the mysteries, and caverns that may not be trodden are hollowed out for this reason. Moments and places are chosen that know how to conceal the inspired celebration of the mysteries.
[2.5.3] Only so much perchance it is safe to say, and cloaking the inviolable to what extent we may, we say it, how that Osiris in his old age was more glorious than in his youth. The gods gave him as a reward to rule over the state with greater prestige, so as to be shown as one superior to injury from men, and the prosperity which he had given the Egyptians, but made by its development incomparably superior to its former state. So the former seemed to be merely a prelude to the latter, and nothing but a promise once sung by the Greek poets, how that the virgin who is now a constellation (and whom we call, I think, Justice),
 on the earth dwelling aforetime
Face to face met all men, nor ever of mortals disdained she
E’en in that far distant past the tribes or of men or of women.
With them she mingled and there took her seat, though a goddess immortal.note[Aratus, Phaenomena 101 ff .]
[2.5.4] how she stayed under the same roof with man –
For in that time men knew naught of bitter discord, of struggle,
Of contestations that menace, of all the tumult of battle.
Thus their lifetime they passed,and the harsh sea was far away from them,
Nor did ships come to bring them supplies from lands o’er the ocean;
Theirs were the plough and the oxen, and theirs that queen of the people.
Dikê, ’t is she who dispenses by thousands her gifts of all justice.
So bloomed this age for a span when the golden race the earth nourished.note[Aratus, Phaenomena 108 ff.]
[2.5.5] He says, then, that as long as men did not use the sea they were golden and had dealings with the gods, but when ships came to them for the service of a strenuous life, then Justice flitted so far away from earth, that she could scarcely be seen on a clear night; and to be sure, when she is visible, she offers us an ear of corn instead of a rudder. Probably she would come down to us now and would again speak to us face to face if we busied ourselves with agriculture, and despised seafaring.
[2.5.6] Now no other period has attained to this that the poets sang of long ago concerning her, save only the period of the glorious reign of Osiris. And if the gods, when bringing him back from exile, did not at that very moment put everything in his hands – let us not hold a contrary view on this score. It is not in the nature of a state to change suddenly for the better, in the way that is changes suddenly for the worse; for evil is a thing self-taught, whereas virtue is acquired only through toil. Needs must that those who purify first should intervene, but that the divinity should move leisurely and in order. But Osiris, before he entered upon a life of action, had to see and hear many things, for many a report is kept away from a king.