It's interesting seeing some of the errors present in something less than a century old on the topic. "In the earliest times of which we have definite history

It's interesting seeing some of the errors present in something less than a century old on the topic. "In the earliest times of which we have definite history everybody believed in many gods." Eh, not quite. You have Philio of Byblos claiming the Phonecian mysteries per Sanchuniathon from around the time of the Trojan War were both about how life began as senseless creatures in mud that eventually became watchers of the sky, and that the history of the pantheon was in fact human inventors deified after the fact. Here is an excerpt: From its connexion Mot was produced, which some say is mud, and others a putrescence of watery compound; and out of this came every germ of creation, and the generation of the universe. So there were certain animals which had no sensation, and out of them grew intelligent animals, and were called "Zophasemin," that is "observers of heaven" This is further strengthened not only by the discovery of the pantheon in Ugarit which matched the one described, but also in the records of Ramses III about the end of the 19th dynasty under foreign invasion he claimed that they "made the gods like men" and had city governors making decisions in place of a Pharoh (the Phonecian style of government were city states). You see the concept of senseless creatures from mud growing into intelligent beings again in Leucretius a millennia later where it is coupled with an explicit description of survival of the fittest in book 5 of De Rerum Natura. So atheism and a rejection of supernatural divinity or first movers may go back far further than the author seems to think. As for his thinking Christianity owed much to Orphism, he'd clearly been reading George Frazier's Golden Bough, which has since been broadly rejected by scholarship. And further, he seems to be unaware that at the time ancient Greek authorities (specifically Atrapanus of Alexandria) had claimed Moses taught Orpheus the mysteries, so first century Judaism was already seen as connected with that specific set of beliefs separate from any direct syncretism.