 ZFC set theory is an account of a cumulative hierarchy V of pure sets, built up, ultimately, from the empty set ∅. Each set within V is ‘formed’ by some ordinally indexed rank. The ranks are cumulative, and are generated, at successor ordinals, by application of the power-set operation. The erstwhile types are born again as ranks, except that ranks are cumulative—every rank contains all members of lower ranks. Their members are put on all fours, so to speak, for they are taken to occupy one single extensionalized, untyped universe V of sets. 