I did the Axial Age five years ago from the perspective of the relationship between religion and technological change. Let's come at the issue of learning, literature, scripts, and the problem of finding the "there," there.
Wikipedia's article on the individual it designates as Siddharta Guatama is entitled "The Buddha." in Buddhist theology, Prince Siddharta is one of a number of soteriological figures designated as "Bodhisattvas." I hesitate to refer to him as the first among equals, but that's the sense of the concept that I am going with, and one of the most important things that distinguish him from other Buddhist saviour figures is that he is considered to be a historical figure, "a wandering ascetic and religious teacher who lived in the eastern Indo-Gangetic Plains during the 6th or 5th century BCE." One of the odder things about this conversation is that their is a tradition that places his life a century before Ashoka, who is fairly firmly dated to c. 250. Given that archaeologists have suggested that the picture of the state of civilisation in this region in the biographical stories of the Buddha more nearly fits 350BC than 550BC, you would think that the conversation would take this tradition more seriously. The introduction goes on to point out that the Buddha is first attested in c. 250, but this turns out to depend on the Ashokan attribution of the Lumbini Pillar, which refers to the Emperor in the third person and past tense, undermining the dating claim. It was also a discovery of notorious fraud Anton Fuhrer. As a practical matter, the Buddha's existence is first affirmatively asserted in Greco-Roman literature by Clement of Alexandria. One would think that he would be a fascinating figure in early Christian Alexandria, well worth discussion.
If, however, the Buddha lived in "the 6th or 5th century BCE," he was contemporary with . . . well, here's another level of difficulty. Per no less an authority than Plato, this was the age of Zoroaster, but Wikipedia, intending to present the consensus of scholarship, or as close to such as can be achieved, puts Zoroaster at 1500BC. The argument is that the Avestas (not attested before c.1200AD) have linguistic parallels with Vedic literature, and on the argument that the Indo-European languages arrived in India about 1500BC, this must be Zoroaster's flourit, not withstanding the authority of Plato and various etymological problems, of which the historian of technology must insist on the claim that "Zarathustra" means "Manager of Camels," and that camels were domesticated once and for all during the Iron Age. To this (non-)contemporary we add Laozi, almost certainly a fictional character and unlikely at best to have been a pre-Confucian figure if real, but certainly claimed as such in the Daoist tradition, and the Seven Sages of Ancient Greece, and let's not even get started on them!
It seems as though arguing about the historicity and dates of the Buddha, Zoroaster, and Laozi in the same breath is a bad thing to do. It is weird that the traditional historical dates of the spread of Indo-European should be on the same level, but they are, and at the end of the day we launch into yet another realm of mystery by noting that these contested claims of contemporaneity (and more besides, as the Wikipedia account shoehorns in Jainism and "Second Temple Judaism") are in service of Karl Jasper's axial age, which cannot be better summarised than as this . . .
But in the Iron Age.
