 This way of describing the iterative picture suggests that the ordinal numbers were somehow present  “before” all the iteration takes place, or at least that they have a life apart from the rest of the sets.   There is a different way of understanding the iterative conception, one that emphasizes the  harmony between the iteration of the power set operation and the Replacement Axiom: as one iterates the power set axiom, more and more well-ordered sets appear. Replacement allows us to decorate these well-ordered sets, creating new ordinals in the process.  Thus the whole picture is one of balance. Indeed, this point about balance can be phrased without reference to any “iteration” at all: there is an equilibrium in the set theoretic universe between the “sideways” push of the Power Set Axiom and the  “upward” push of the Replacement Axiom.[8] 