Think about it. Okay, if you don't have anything better to do for a few minutes, or if you are in the process of procrastinating about something else and need a distraction, think about it. Maybe I should already know this answer, given all the different snippets about cultures and religions that I have read in the past three years, but I don't.
This rosette was planted on this piece of glass as a mini-homage to the symbols found in Southeastern Ceremonial Complex art. You can click on the link and read more about the Mississipians, mound builders, and Cahokia, but this is a wider topic, one that spans the immensity between those four corners of the earth. The rosette is really just another version of a cross, and the cross as a symbol spans time and earth. Someone had to be the first person to come up with the idea of crossing two lines to indicate directions. Actually, if you think about it, two directions (a single line) don't provide enough reference points to give someone directions, three directions (a sort of inside out triangle) would not allow for opposing directions (which have to make it easier to describe things), and more than four directions (say, the eight points on a compass that shows not only N, E, S, and W, but also NE, SE, SW, and NW) is really just an elaboration on four. As for the names and orientations of those four directions, they would eventually have to be universal, or directions would mean nothing.
Ah, but this must have been an idea that has been discovered many times over, by many people who were each facing the need to describe directions and indicate places. You almost have to argue that such a basic concept becomes elemental to cultures, too. It becomes not only a way to tell each other how to get to specific places, but also a way to organize your thoughts and beliefs about the world. Sun rises in the East and begins the day. Sun sets in the West and ends the day. Eventually, the connection is made with the inner world, with beginnings opposite endings and heavens opposite underworlds. From there, crosses in all their many forms seem a natural choice to symbolize the workings of the spiritual world.
Just think about it. How many people independently stumbled and rambled upon the idea of "the four corners of the Earth"? Amazing to think about, isn't it?