Solids and Cavities in Architecture

As we've said before Architecture is within art.Architecture is the art of playing with solids(forms) and cavities(space),that are very essential components of architecture.Cavity is the clearly defined space.Rasmussen use a different word cavities, instead of spaces and voids,because void is undefined and space is overdesigned.On the other hand the solids enclose and form the cavities.In other words,solids are the containers and the cavities are the contained.Rasmussen also make  a kind of parallelism ,let say the relationship between solids and cavities,glasses and liquid.The glass it self is the solid and the liquid is the cavity.That's how he tries to make a simple example to understand better the relationship.
Architecture is a "game",how we play with solids and cavities.
Rasmussen says there are two types of architects, who differ from the way they start designing.One is sloid-minded and the other one is cavity-minded.So the architect might choose to start designing firstly with main space.He/she might think about the space and other detais late, but some others might have other approaches.Furthermore Rasmmussen gives examples of works  of these types of architects.In the Gothic architecture is characterized by solid-minded.The Beauvais Cathedral in France  is the right example of the solid minded design.First thing we can see is the sharp pointed structure.While the cavity minded design belong to the period of Renaissance.Like in Karli in India cave temples,St.Peter church,etc.
Another period is Late Renaissance or Mannerism.This period followed Renaissance architecture in a more sophisticated manner.Mannerism was the dominant art form of the Late Renaissance.In those buildings that were build in that period,we can distinguish the contrast between the solids and cavities create visual drama in architecture.The employment of masses and cavities together in effective contrasts leads to works that use grand architectural/visual effects.We can observe that effective use of contrast in many edifices and buildings.In buildings like: Porta di Santo Spirito,Italy; Palazzo Massimo alle Colonne In Rome; S.Maria della Pace in Rome,Fontana di Trevi,Police Headquarters,Copenhagen city Hall etc.This contrast was strongly reflected in one of the modern design of "Falling Water"(Johnson Wax), particularly in the importance of interpenetrating exterior and interior spaces .
The relationship and the contrast between the solids and cavities are part of the design and is important how we use them,both to be in control.A good architect should look on all sides,not only the space part but the structure too.