“The democratic gospel was both lofty and realistic. It had a high historic mission, but it was based on the idea that biblical morality is necessary precisely because people are selfish and shortsighted, capitalism is necessary because economies are too complicated to understand and plan; democracy is necessary because concentrated power is always dangerous, no matter how seductive it seems in the short term.”
One wonders whether Brooks wrote that with approbation or disapproval, since he uses the appositive “but.”