Rome is the ultimate city, the defining metropolis, that same civis from which the fundamental concept of civilisation derives. The place enshrines extremes of human grandeur and baseness like no other, reminding us of the enduring paradox of our species – that transcendent resources of imagination, faith and creativity can exist alongside barbarism, arrogance and folly. Whether living in Rome or looking at it, we learn by degrees something about who we are.

For the art critic and social commentator Robert Hughes in Rome (Weidenfeld & Nicolson 528pp £25), this Roman learning curve has two alternative starting points. One is Campo dei Fiori, that distillation, within a single piazza, of the entire urban experience, best savoured on a spring morning when