I think both these statements are true. Trends in architecture impact other art forms and the culture as a whole. Environment is arguably as important a factor to who we become as our genetic codes. in cities, architecture is the environment, at least in the symbolic sense.
Monumental buildings signal where as a society we should be placing resources and investing our interest. What drives any society can be understood by looking at the buildings that are built to last.
In ancient Egypt, royal tombs were meant to last for eternity; in ancient Greece, public buildings, places of learning, and temples; in Rome, roads, bridges, aqueducts- the infrastructure of civil order and military supply. Medieval Europe was like a circulatory system made up of cathedrals and fortresses- either moving foreign populations into areas or keeping them out as needed.
Throughout early America, banks, churches, and courthouses in every town were built ornately of stone. Our contemporary palaces are likely to be commercial buildings and corporate headquarters.