C The Aztec Empire was conquered by Hernán Cortés in 1519
Thoureau wanted to poit to the fact that following traditions limits us and deprives us from developing our imgination. Thoreau, like other romantic authors, does not agree with tradition. He thinks it prevents people from finding true greatness and blocks their path to spirituality. "Castles in the air" are simply illusions by which people persuade themselves in something that is not true, in Thoureau's opinion.
