The architectural remnants of the age cannot be avoided. They endure–with their windowless façades, their human-repelling scale, their masses of dirty concrete and their self-conscious wish to shock. Worse things happened in the 20th century, but few were more puzzling than the way Americans let their landscape be ravaged by architects and planners, particularly in the years between World War II and the 1980s. … Josep Lluis Sert’s ghastly Holyoke Center still occupies the spot in Harvard Square where Massachusetts Avenue’s beautiful line of Victorian brick was ripped apart to make way for it in the 1960s. Gerhard Kallmann’s Boston City Hall still sits like a Stalinist mausoleum on an empty, windswept plaza, for which dozens of ancient city blocks were razed. You can work westward from there. …

Around 1980, at the very moment these horrid buildings seemed to be proliferating uncontrollably, legitimacy was somehow stripped from orthodox Modernist architecture, through a process as mysterious as the one by which it was conferred. Some of the credit goes to one of the most bizarre books in the history of architecture: Learning from Las Vegas (1972), by the Philadelphia architect Robert Venturi, his architect wife Denise Scott Brown, and Steven Izenour.

The book is a diptych. The first half catalogs, soberly, the architectural features and design logic of the casinos and motels along the Strip (today Las Vegas Boulevard). This part of the project was undertaken with the help of graduate students working inside the Yale School of Art and Architecture –a building, designed by the school’s own dean Paul Rudolph, which can lay a plausible claim to be the ugliest structure ever built in the United States.

The second half of Learning from Las Vegas is a polemic (generally a polite one) against Rudolph and other myrmidons of the Swiss master theorizer and charlatan Le Corbusier. Modernist architects sneered at commercial strips as tacky, simplistic, and bourgeois. Venturi et al. pitted the unruly architecture of Las Vegas (most of it designed by private businessmen) against the logical, doctrinaire architecture of the academic modernists (most of it designed for the public sector) as a way of showing up the latter. What makes Learning from Las Vegas so fascinating is this trick of deploying one kind of crap to discredit another.

Las Vegas is disorienting, and disorienting in a way that can be expected to generate bad architecture. Very fast automobile traffic is to blame. On highway off-ramps, you turn right to go left, Venturi notes. A person can no longer trust his sense of where he is and where he is going; he needs to be told. In Las Vegas, signs perform this function. What they tell you is to enter this or that casino. They need to do this as simply as possible, since the readers of those signs are operating a dangerous piece of machinery at 70 mph. So complex manipulations of space, the modernists’ bread and butter, were out of the question. Symbolism had to be blunt, unchallenging, and appeal to some prejudice or preconception: Roman columns on Caesars Palace, an Arabian lamp on Aladdin’s. Nothing could be tackier.