Why We Build, By Rowan Moore. Picador, £20

At school, Rowan Moore would have been the standoffish boy whose demeanour conveyed distracted impatience, but who then asked a very good question. This intelligent and cultured book has those qualities. Why We Build is a humanist's plea for architecture founded – to borrow Paul Simon's lyric – on the "incidents and accidents" of lives and places, rather than on marketing scripts or architectural heroism.

Why We Build is not a destructive polemic; it champions the unexpected and the non-iconic – spaces and people, rather than vacuous mortuaries masquerading as brilliant architecture. He is astringent and subtle on the psychopathology of the British architectural establishment, a profession "incubated by personal dysfunction. You might say that part of its DNA is to miss the human point". Moore's convictions are embedded in architecture's febrile human factors: "Hope, sex, power, money, ideas of home, the sense of mortality." The book's leitmotif is the Brazilian architect Lina Bo Bardi, who once said that she wanted her Pompeia centre in Sao Paulo to be ugly because "its beauties should come from people rather than buildings".

There is nothing evasive about Moore when he goes into attack-dog mode. Several years ago, he pilloried architecture's Zeus, Norman Foster. The big beast that interests Moore most in Why We Build is Richard Rogers. Moore is by no means crude in his criticisms of the pink-shirted maestro but he homes in remorselessly on the architectural and political cant in some of Rogers's major works. The Millennium Dome demonstrated "a willingness to spend huge amounts of money on almost anything except what might be useful, or thoughtful, or good".

Last year, I stood with Moore outside the vast, twisting form of Zaha Hadid's MAXXI Museum in Rome. "It's a bit like Laocoön," he said, referring to the myth of the Trojan priest strangled by God-sent serpents because he wanted to burn the Trojan Horse. Moore is not quite a contemporary Laocoön. His book, though, is a kind of Trojan Horse, packed with passionately held ideas about the epiphanies, farces and humanity in architecture.