Your comment begins with the fair assumption that I'm not a complete postmodern relativist, although I go far towards that side elsewhere, in arguing on neo-Kantian grounds that all knowledge is at least partly subjective (links below). But your comment ends with strawman criticisms. So I'll try to be brief.
I think science takes us closer to the facts than, say, religious or children's fantasies. And that's so even though I criticize science as having a Promethian/Faustian/Luciferian agenda of dominating the wilderness and replacing it with civilization. So I don't go all the way into postmodern antirealism and relativism, but I go part of the way, into pragmatism and existentialism.
Nowhere do I say children's perspectives aren't "valuable or truthful." On the contrary, I argue for a pantheistic upshot of atheistic naturalism, which may re-enchant nature and return us to a form of animism. But naïve conceptions of the truth aren't the same as hyper-rational, alienated ones.
Likewise, I don't see why writing need be the key dividing line. I don't have a strong opinion about when behavioural modernity emerged. But the Stone Age was 2.5 million years of hardly any apparent technological development. There's an innocence to animal consciousness that's naïve in its relation to the rest of nature, and both Stone Age people and children approximate that naivety. That's just a hypothesis, but it seems to fit the data.
Moreover, nowhere do I say that modernity is fully grown up. On the contrary, I write elsewhere about the prospects of transhumanity. But yes, relative to Stone Age animists, modern scientists are pretty grown up, and relative to potential transhumans, those same scientists will seem childlike.
