Andrew Ross Sorkin

Bringing back something akin to Glass-Steagall would clearly help limit risk in the system. And that's a very good and worthy goal. Letting banks sell securities and insurance products and services allowed them to grow too big too fast and fueled a culture that put profit and pay over prudence.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.