Full Idea
Spengler relies upon the idea of human cultures as organisms which grow and then inevitably die, having lost their vitality.
Gist of Idea
Human cultures are organisms which grow, and then fade and die
Source
report of Oswald Spengler (The Decline of the West [1918]) by Andrew Bowie - Introduction to German Philosophy 2 'Herder'
Book Reference
Bowie,Andrew: 'Introduction to German Philosophy' [Polity 2003], p.52
A Reaction
He should have thought more about technology. If the 'West' collapses and is replaced by China (say), the new Chinese culture will be barely distinguishable from the West, because they will pursue similar technologies.