Full Idea
The limitation of size conception of sets justifies the axiom of Replacement, but cannot justify Power Set, so NBG set theory appropriates the Power Set axiom from ZFC.
Gist of Idea
Limitation of Size justifies Replacement, but then has to appropriate Power Set
Source
Keith Hossack (Knowledge and the Philosophy of Number [2020], 09.9)
Book Reference
Hossack, Keith: 'Knowledge and the Philosophy of Number' [Routledge 2021], p.147
A Reaction
Which suggests that the Power Set axiom is not as indispensable as it at first appears to be.
Related Idea
Idea 23624 The iterative conception has to appropriate Replacement, to justify the ordinals [Hossack]