Edward Gibbon's assessment of Julian

Rather than attempt to match the elegance or lucidity of Edward Gibbon, rather than attempt my own appraisal of Julian, I will simply tell you what Gibbon said in The Decline and Fall of the Roman Empire, Volume II, published by Alfred A. Knopf, Inc. and copyrighted in 1910. Edward Gibbon writes in chapter XXII, page 406:

Whatever had been his choice of life, by the force of intrepid courage, lively wit, and intense application, he would have obtained, or at least he would have deserved, the highest honours of his profession, and Julian might have raised himself to the rank of minister or general of the state in which he was born a private citizen. If the jealous caprice of power had disappointed his expectations; if he had prudently declined the paths of greatness, the employment of the same talents in studious solitude would have placed beyond the reach of kings his present happiness and his immortal fame. When we inspect with minute, or perhaps malevolent, attention the portrait of Julian, something seems wanting to the grace of perfection of the whole figure. His genius was less powerful and sublime than that of Caesar, nor did he possess the consummate prudence of Augustus. The virtues of Trajan appear more steady and natural, and the philosophy of Marcus is more simple and consistent. Yet Julian sustained adversity with firmness, and prosperity with moderation. After an interval of one hundred and twenty years from the death of Alexander Severus, the Romans beheld an emperor who made no distinction between his duties and his pleasures, who laboured to relieve the distress and to revive the spirit of his subjects, and who endeavoured always to connect authority with merit, and happiness with virtue. Even faction, and religious faction was constrained to acknowledge the superiority of his genius in peace as well as in war, and to confess, with a sigh, that the apostate Julian was a lover of his country, and that he deserved the empire of the world.