It must be admitted that there is a degree of instability which is inconsistent with civilization. But, on the whole, the great ages have been unstable ages.
Civilizations can only be understood by those who are civilized.
Without adventure civilization is in full decay. ... The great fact [is] that in their day the great achievements of the past were the adventures of the past.
Civilization advances by extending the number of important operations which we can perform without thinking about them. Operations of thought are cavalry charges in a battle - they are limited in number, they require fresh horses, and must only be made at decisive moments.
Without adventure all civilization is full of decay. Adventure rarely reaches its predetermined end. Columbus never reached China.
It is the business of future to be dangerous.... The major advances in civilization are processes that all but wreck the societies in which they occur.
Without adventure civilization is in full decay.