Full Idea
For Herder, we cannot attain to the highest ideals of all the centuries and all the places at once, and since we cannot do that, the whole notion of the perfect life collapses.
Gist of Idea
We cannot attain all the ideals of every culture, so there cannot be a perfect life
Source
report of Johann Gottfried Herder (works [1784]) by Isaiah Berlin - The Roots of Romanticism Ch.3
Book Reference
Berlin,Isaiah: 'The Roots of Romanticism' [Pimlico 2000], p.65
A Reaction
Herder seems to be the father of modern cultural relativism. The idea is hard to challenge, but the ideals of some cultures should be ignored, if they diminish rather than enhance the good life for all.