ABSTRACT
The most apparent part of a building is its struc-ture, or what makes it stand up. This has been more obvious since the mid-twentieth century, when architects and engineers took particular delight in making structures do more work with less material, seemingly in defiance of gravity, while showing the structure more clearly. The tension we may feel when looking at a modern structure so delicate as to seem in danger of imminent collapse illustrates the difference between the physical structure, that is, the “bones” of the building that do the work, and the perceptual structure, or what we see. They are not the same, for a column may be much larger than structurally necessary in an engineering sense simply to reassure us that it is indeed big enough for its job. Such is the case with the extraordinarily thick columns of the Temple of Poseidon at Paestum, Italy [3.1, p. 32].
