I currently listen to an online course on religious symbolism. In the last lecture about the symbolism of time and space, there was the following thought. Ancient people didn't separate time from space, it was one thing - the universe. As well as they didn't separate the visible world from the invisible. For example, in ancient Egypt there were three worlds: visible tangible, visible intangible, and invisible, but they all were united and inseparable from each other.
Then I've got a thought. It is said in the lecture that this is a feature of ancient people. In the course, it was also mentioned that people of different religions have something in common – craving for unity with the Beginning. It turns out that in this religious people are closer to the ancient. And there is a quite widespread thought (presented even in some branches of Buddhism), that humanity gradually loses this knowledge/feeling.
So, my thought is that it turns out that we have a way from the united to the separated. And the further we go, the more everything is divided. Why? Probably, the thing is in cognition and in the specifics of how people learn things. That is: people described something, studied it, learned, set boundaries to it, defined the key features, gave a name to it – and by that they distinguished it, and separated from the rest. In such a way people separated different sciences, distinguished different chemical elements, gave different names to music styles, etc. People have this tendency to distinguish, give names, categorize. And in this we get the way further and further away from the One.