Onfray rule his account to Gnosticism in which he sees a mess doctrinal ignoring any possibility of esoteric meanings camouflaged. I wait to read what this author thinks of esotericism of Kabbalah, of The Secret Doctrine, Volume 1: The cosmogenesis - Cosmic evolution - The stanzas Dzyand'Helena Blavatsky and the Treaty on the seven rays. Volume 1. esoteric psychology. Alice Bailey to judge a potential bias.
It's hussar qu'Onfray approaches his subject without ever looking into the details. So page 155 the author speaks of the Church (Sylvestre 1) who would receive the rule of Constantine on the four main seats (Antioch, Alexandria ..) But at that time we can not talk about church. Christianity out of his proto-orthodox to become Orthodox and remains under the authority of the regional bishops. Also speaking of the Church restricting this term only to shorten Bishop of Rome is the history of almost 800 years, as well as to call this the Roman Catholic Bishop Pope sense that claims to establish a line with St. Pierre .
Further Onfray tells us that the empire became Christian under Constantine 1. Wrong! Constantin has allowed and encouraged Christianity and it is itself converted on his deathbed. Not until Theodosius (and Gratien for Western Empire) for this time Christianity was elevated to a state religion after Julian the Apostate attempted to restore paganism.
Let's talk about precisely Julien. Page 251/252 Onfray does not contradict Montaigne tells us that this can not be Julien Apostate because he was not a Christian. Re wrong! Perhaps Montaigne did not know but since we learned that Julian the Apostate had just been brought in Christianity, Arianism exactly.
For the rest I remember a long passage devoted to Montaigne, but who appeared to be in the loop to return constantly to the same argument. In total a book that scatters. I do not doubt in any case of scholarship and quality of the author and to respect the remarks that I am here I must say frankly I was not at Nicaea and have not experienced personally Julien nor Constantine. But it is not I the writer nor the philosopher, much less a historian but as a reader I would hope more precautions to be at least mentioned the different contradictory theories may take up the subjects covered.
Some lawyers are best known on TV or radio that court, could it be the same with philosophers too eager to publish.