Have you looked it up in Bartlett's _Familiar Quotations_ and
other similar references?
Henry Grunder
Conservation/Preservation Coordinator
The Library of Virginia
                    "Hustling libraries shamelessly"
According to [log in to unmask]:
>
> Anyone know what philosopher said this and what it means?:
>
> "The owl of Minerva spreads its wings and takes flight only at dusk."
>
> TIA,
>
> - Adrienne
>