The Smithsons, along with Reyner Banham, described their New Brutalism as “an ethic, not an aesthetic,” and that ethic can be said to have had two essential premises. The first was that tough and complex times called for tough and complex architecture. The ruins of World War II (and intimations of a World War III) inspired architecture so massive as to be nuclear-proof but also so special and soaring in form that it might transcend a fear-struck moment. The awfulness of the era called for awesomeness in its buildings. (“It will outlast,” New York Times architecture critic Ada Louise Huxtable wrote of Boston City Hall in 1969, “the last hurrah.”) The second premise was that buildings built by governments, from city halls to public housing, answered to a higher calling than those created by private development, which needed only to be efficient and entertaining. What exactly that calling was and is, and whether structures like Boston City Hall answered it, is a matter of perpetual debate—and that debate, and the notion that architecture can and must summon it, is thrilling.