Full Idea
The Owl of Minerva spreads its wings only with the falling of dusk.
Clarification
The owl is the symbol of Roman wisdom
Gist of Idea
Wisdom emerges at the end of a process
Source
Georg W.F.Hegel (Elements of the Philosophy of Right [1821], Pref p.13), quoted by A.W. Moore - The Evolution of Modern Metaphysics 07.4
Book Reference
Moore,A.W.: 'The Evolution of Modern Metaphysics' [CUP 2013], p.174
A Reaction
Hegel explains that this means that wisdom is the product of historical maturity, as the ideal emerges, and illuminates what is real. I think.