Some buildings are more important than others. It would be unthinkable for example to write a book about ancient Greek architecture without mentioning the Parthenon (Figure 7), but the Temple of Aphrodite on Kythera could be missed out without the study necessarily seeming incompetent. It was an important temple in its day, but its ruins are not now visible. In fact the remains of genuine ancient Greek temples are rare enough for it to be possible in a book-length study to mention all of them, or at least all of those where excavation has restored the impression of a substantial building on the site. In the ancient world there were far more temples, some of them perhaps in perishable materials that have vanished without trace. The passage of time has reduced the number to something manageable. There are times and places where even less has survived. For example in Anglo-Saxon England (the period between the departure of the Romans and the arrival in 1066 of the Normans) most of the buildings were made of timber, and they have rotted away leaving little for anyone to find. The buildings that do survive were — unusually — built in stone, and they survive in fragments, because they have been extended or rebuilt over the years. Houses on the whole were not built in stone, but churches sometimes were; and where the church was part of a settlement that thrived and grew, the church was remodelled or rebuilt at some point during the thousand years and more that have passed since then. The few Anglo-Saxon buildings that we know are therefore churches from settlements that were at their most important a thousand and more years ago, so civic pride never took over to build a more magnificent Gothic church. In recent decades the knowledge of buildings has been supplemented by information inferred from the remains of timbers that have rotted in the ground. Rotted timbers change the colour and consistency of the earth that has claimed them, and if the site has not been built over in the mean time, or ploughed with a deep modern blade, then it is possible to guess what the buildings might have been like. So, if we are trying to put together a picture of Anglo-Saxon architecture, we find that the positions of discoloured samples of earth are important evidence for us, and we would not dream of ignoring a surviving house, if one were ever to be authenticated. Historically it would be sensationally important, even if it were an unprepossessing little building.
If we are trying to write a history of modern architecture then we have exactly the opposite problem. There is too much of it to be able to mention everything, and almost everything in fact has to be left out. In a large modern city the largest modern buildings are likely to be commercial — office blocks, shopping malls, multi-storey car parks, and so on. These buildings tend to be edited out of the picture presented in an architectural history, because the buildings do not seem to be culturally significant. There are rare exceptions, like the Seagram Building in New York (Figure 18) which has an unusual status, for reasons that will be explained. Even buildings of great prominence and visual interest (like the Philadelphia City Hall) do not have a wide enough cultural significance to justify their inclusion in a traditional overview, whereas a small house like the Schröder House (Figure 9), tucked away inconspicuously out of the centre of Utrecht — itself a much smaller city than Philadephia — is one of the best known buildings of the 20th century. Among architects it is without question the best known 20th-century building in the Netherlands. In fact among architects outside the Netherlands it is probably the best known building of any age in that country. And this is despite the fact that in central Utrecht, in a prominent position, there is a spectacular post office, dating from about the same time. It is adventurous in its use of materials, making the traditional Netherlands bricks into a series of parabolic arches with glazing between them, so the post office’s central hall is flooded with light in a spectacular way. It is a more prominent building, more technically accomplished, and its interior is just as striking, and yet only a specialist would know who designed it, and it is seen to be of only local interest.