Most critical is the appearance within the room of a dominant, coherent center formed by exterior view, space, ceiling, and windows.

Entities in the same semantic neighborhood but without a typed relation to this one — candidates for new edges or unrecognized duplicates.

• The appearance of this invisible and useful center at the core of every room is the most subtle invariant.claim0.811
  Underlines the difficulty and importance of the focal center.
• Usually the main center of a room is defined by two things: it is a quiet spot in the pattern of movement and a place near the light.claim0.802
  Operational definition of a room's main center.
• Space is a material whose most important feature is its capacity to form centers.claim0.797
  Reiteration of a key premise from Book 1 within the new metaphysical framework.
• It is, above all, the light and relation to movement and relation to the whole which give quality and character to a room.quote0.793
  Summarizes the three primary determinants of room life.
• Even when a room contains major asymmetry, the composition of space will be such as to create a combination of locally symmetric centers.claim0.772
  How asymmetry can still be alive.
• The space in the angle between the wall surface and the overhanging top is itself a center, and must be made as positive and being-like as possible.claim0.771
  Alexander's demonstration that even the negative space beside an overhang requires conscious I-directed attention.
• The centers which bring life to a room are larger features which lie beyond the boundary of the room.claim0.770
  A key insight about position and context.
• Centers are above all, labile, they are foci of wholeness, they are not things, but regions, qualities, focal points of centeredness.quote0.768
  Key definition capturing the non-atomic, relational nature of centers as fields rather than objects.