After Lyndon Johnson's Great Society, the belief in decent housing as a political right or social obligation was supplanted in the U.S. by the notion that suitable shelter should be an act of charity.

Avant-garde architects have never been able to depend on the support of the establishment, since the customary patrons of this most conservative and slowly moving art form have historically been resistant to innovation and experiment.

The work that launched Snohetta into the architectural big leagues was their Oslo Opera House, which will certainly rank among the firm's highlights whatever else they may do. Although this is by any measure a triumph of city planning, the building itself is not quite a masterpiece, though very fine indeed.

Before World War II, Modernist architects sometimes had to resort to custom fabrication or outright fakery to achieve the machine imagery advocated by the Bauhaus after its initial, Expressionist, phase. Stucco masqueraded as reinforced concrete; rivets were used for decoration.

During the modern period, the vanguard architect has usually relied on small residential jobs both to supply a steady income and to serve as 'sketches' for ideas that are often later translated to the larger scale of public commissions.

What a museum chooses to exhibit is sometimes less important than how such decisions are made and what values inform them. To have the crucial role of museum professionals usurped by self-serving tycoons in the name of economic imperative threatens not only the integrity of individual institutions but the very principle of art held in public trust.

High among the unpredictable variables that endanger the survival of worthy buildings are the vagaries of taste.