Laudator Temporis Acti

Erwin Panofsky (1892-1968), Meaning in the Visual Arts: Papers in and on Art History (Garden City: Doubleday Anchor Books, 1955), p. 7 (footnote omitted):

Every historical concept is obviously based on the categories of space and time. The records, and what they imply, have to be dated and located. But it turns out that these two acts are in reality two aspects of one. If I date a picture about 1400, this statement would be meaningless if I could not indicate where it could have been produced at that date; conversely, if I ascribe a picture to the Florentine school, I must be able to tell when it could have been produced in that school. The cosmos of culture, like the cosmos of nature, is a spatio-temporal structure. The year 1400 means something different in Venice from what it means in Florence, to say nothing of Augsburg, or Russia, or Constantinople. Two historical phenomena are simultaneous, or have a determinable temporal relation to each other, only in so far as they can be related within one "frame of reference," in the absence of which the very concept of simultaneity would be as meaningless in history as it would in physics. If we knew by some concatenation of circumstances that a certain Negro sculpture had been executed in 1510, it would be meaningless to say that it was "contemporaneous" with Michelangelo's Sistine ceiling.