51it exercises a pull; we feel uncertain there, and therefore re-
turns to the periphery, only to turn back towards the mid-
dle again, so that perception and movement begin to oscillate
(> oscillation) indecisively between periphery and centre.
Only when certain elements or functions provide a focus does
the centre become a prevailing attractor. From time immemo-
rial, hearths (Latin: focus), altars and fountains have fulfilled
this function. The same function, however, can be served by
any element that attracts attention towards the centre or in-
duces people to gather (> gathering) there, whether an exhibi-
tion object, or a table that has been shifted into the light for
a common activity; in the latter case, we strive towards the
centre, in the former, we orbit it (> circulation).
Spaces that are simultaneously centred and directional
may be imbued with a double focus; examples are the two
positions of an altar either in the chancel or in the (transept)
crossing of a church. During the Baroque, special effects were
derived from the fusion of elongated and centralized spaces.
Notably, the enclosing structure is less conspicuous in spaces
based on circular plans than in those with oval ones: in a cir-
cle, optical perception is so strongly compressed by perspec-
tival foreshortening that the impression of enclosure is barely
effective. When we enter a space with an oval plan along the
long axis, the perspectival foreshortening in the lengthwise di-
rection deforms it visually, causing it to appear as a circle; af-
ter a few steps, we feel strongly contained and constrained by
the walls. Baroque architects such as Johann Michael Fischer
employed these effects in their church buildings so that the
nave enclosed the congregation, while along the lengthwise
access, the altar seems to occupy the centre.
The total composition of the building and all of its rooms
can be organized hierarchically around a main, central room,
so that the character of the building as a whole emanates
from this centralized position and its significance. Even where
the centre recedes functionally behind the peripheral rooms
as an ‘empty middle’, its latent spatial significance for the