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 1.4
[1.4.1]  Now when he took his seat in the guise of one who conducts public affairs, he showed clearly that all evil takes every form, for it is at war both with virtue and with itself, and both the opposing forces are part of it. And this gaping idiot straightaway became downright mad, and barking more sharply than a Molossian hound, he would bring disasters, one on a private individual, another on a family, or again on a whole city, and he quite rejoiced in having worked a greater evil, a if thinking to wash away the dishonor of his indolence at home with the tears of men. One point a man might gain from this evil plight, that oftentimes when on the brink of doing a dreadful thing, or through perversion of judgment he would degenerate into odd suspicions so as to resemble the fanatics, and would bellow forth vigorously about the shadow at Delphi; and meanwhile the person in danger would make his escape without any further mention being made of him: or he would be overcome by lethargy,  and his brain would be fuddled for some time, to such an extent that his mind was far away from his surroundings. Then, when he had pulled himself together, even so all memory of the recent incidents had escaped him, and he would dispute with members of his administration about how many ears of corn a medimnus contains, or how many cyathi a chous, giving evidence of a rare and amazing shrewdness. Many a time did sleep save a man from misfortune, for it would overtake Typho at a very opportune moment, and would even have pushed him headlong from his throne, had not an attendant dropped his lamp to support him.
[1.4.2] Thus oftentimes a tragic night-festival would end in comedy, for he never transacted official business in the daytime, inasmuch as his character was averse to the sun and the light, and more akin to darkness. Though knowing well that everyone who had even a small share of sense accused him of the most complete ignorance, he did not blame himself for his eccentricity, but rather on this very account did he become the common enemy of those who had intelligence, as if they were wronging him in knowing how to pass judgment. The man was without resource in counsel, but most resourceful in plotting. Folly and madness were ever with him, evil destinies of the soul which gain strength from one another. Never have there been, nor shall there ever be, in nature other evils greater than these, and more calculated to extirpate the race of man.