  This undifferentiated mass includes all there is of all the natural ingredients that there are, the ingredients that will eventually form the natural constructs that constitute the cosmos as we know it. Nothing is ever added to or subtracted from this storehouse of stuffs, although the mass of stuffs is not always homogeneous. In fact, there are different densities of ingredients even at this earliest (pre-motion) stage. B1 makes clear that air (dark, moist stuff) and aether (bright fiery stuff) are the most emergent (largest) ingredients, and their dominance means that the original mixture must have been like a dense bright cloud: nothing else would be evident or manifest, even had there been an observer. At some point nous (the time being right) set the mixture in motion and caused it to begin to revolve (first in a small area, and then in an ever-widening area). The rotary motion causes the ingredients in the mass to shift. This shifting produces what Anaxagoras calls “separating off.” Because the mass is a plenum, any separation will be a rearrangement (thus a mixing) of ingredients. The continouous ever-expanding rotation produces more and more separation. The Everything-in-Everything principle continues to hold, so there are all ingredients at all places at all times, but the different densities of ingredients allow for local variations, and so the rotating mass becomes qualitatively differentiated.