I am generally of the opinion that mankind lost its way at some point following the excesses of the absolute monarchies, the Black Death, and the Reformation. I would also consider the First World War to be the mortal blow to the Western culture. The Second one, as well as the Cold War were after effects of the First.
At the start most of the countries in Europe were Christian kingdoms. At the end they were either secular republics or moving that way. Same way with the great unification wars of the mid 1800’s.
It is real hard to pin point where the thread was lost. So hard that I sometimes wonder if the “ideal” ever really existed.