Die Eule der Minerva in Hegels Rechtsphilosophie

The foreword to Hegel’s Philosophy of Right concludes with a though-provoking metaphor: “When philosophy paints its grey in grey, one form of life has become old, and by means of grey it cannot be rejuvenated, but only known. The owl of Minerva takes its flight only when the shades of night are gathering.” How do we understand this enigma and its implications for legal philosophy?