What did G.W.F. Hegel mean by comparing Friedrich Wilhelm Joseph von Schelling’s Absolute to a night in which all cows are black?

G.W.F. Hegel used the comparison of Friedrich Wilhelm Joseph von Schelling’s Absolute to a "night in which all cows are black" to criticize Schelling’s definition of the Absolute as an indiscriminate unity of the subjective and the objective.1

By this metaphor, Hegel argued that Schelling’s conception of the Absolute lacked internal differentiation and specific content. Because Schelling defined the Absolute as a state where all distinctions between the subjective and objective were submerged, Hegel contended that it rendered all individual things indistinguishable from one another, much like how objects become impossible to differentiate in the darkness of night.1

Furthermore, Hegel criticized Schelling for failing to explain how one could logically ascend to this Absolute, noting that Schelling presented it as if it were "shot out of a pistol"—meaning it was asserted without the necessary philosophical derivation or mediation.1