The greatest enemy of justice is privilege.

[Der größte Feind des Rechtes ist das Vorrecht.]

Marie von Ebner-Eschenbach (1830-1916) Austrian writer

Aphorisms [Aphorismen], No. 219 (1880) [tr. Scrase/Mieder (1994)]
    (Source)

(Source (German)). Alternate translation:

The greatest enemy of the law of right is the law of prerogative.
[tr. Wister (1883)]