>Zero was invented by a Persian man with a rather scary last name starting >with Z. The introduction of zero revolutionized the way people look at >mathematics. How did they do mathematics before? I guess they just >considered zero to be the space between two rows of beads on an abacus or if >they did the computations in their head, added 2 to get from 1 to -1. I >really don't know, maybe Steven Gabriel does. I'm interested in what they >did before zero also. I have been under the impression that the concept of zero came about after Islam, and before that, wasn't considered at all. This a very recent discovery in the grand scheme of mathematics. If this timetable is correct, the pyramids were built without the knowledge or acknowledgement of zero, and with a geometry (which i also love) we still haven't completely unraveled. My point is a binary system is one way of looking at things. yes - in a binary system everything boils down to 1 and 0, presence and absence. But the original discussion wasn't even about presence and absence. It was about the differentiation of self vs. other, which is a completely different issue, both being "presences". Although differentiation is important in language, arguably essential, it is not the only essential element. Differentiation without association has no meaning. I can know that two things are opposites, but unless I know what one of those things is already, the differentation means nothing to me. Self vs. other seems toSme to be valuable symbolically only because self is a known (to some extent) quantity. symbols are valuable (or valued) due to the association (be it current feeling or from memory) one has with them. Elizabeth