"Teilhard refers to "Centeredness" as a characteristic of the universe on all levels. Each corpuscle of matter has a centre "within", its principle of organisation. The more complex the being, the greater degree of centreity. Teilhard teaches that Centreity is the true, absolute measure of being in the beings that surround us, and the only basis for a truely natural classification of the elements of the universe. The axis of evolution stretches from the lowest degree of centreity to the highest, and entities having the same degree of centreity constitute "isopheres", forming universal units of the same type of being. So pre-living entities are ordered on Earth in the lithosphere, the hydrosphere, and the atmosphere. Organic beings make up the biosphere, and thinking entities (which in Teilhard's system solely means man) the noosphere. When ranked in their natural order, the whole family of isopheres will define at the heart of the system a focus-point of universal synthesis, the Centre of centres, Omega [Activation of Energy, pp.10-13, 102; Beatrice Bruteau, Evolution towards Divinity, p.138]"

"Teilhard de Chardin's Evolutionary Philosphy"
http://www.kheper.net/topics/Teilhard/Teilhard-evolution.htm