Courtney's edition (1892) is convenient.
Reference may be made to Duff, Spinoza's Political and Ethical Philosophy; Berolzheimer, System der Rechts- und Wirthschaftsphilosophie, II, § 28 (World's Legal Philosophies, 134-141); Dicey, Law and Public Opinion in England, Lect. 6; Albee, History of English Utilitarianism; Stephen, The English Utilitarians; Solari, L'idea individuale e l'idea sociale nel diritto privato, §§ 31-36.
Kant, Metaphysische Anfangsgründe der Rechtslehre (2 ed. 1798). Translated by Hastie as "Kant's Philosophy of Law" (1887).
Fichte, Grundlage des Naturrechts (1796, new ed. by Medicus, 1908). Translated by Kroeger as "Fichte's Science of Rights" (1889).
Hegel, Grundlinien der Philosophie des Rechts (1821), ed. by Gans (1840), new ed. by Lasson (1911). Translated by Dyde as "Hegel's Philosophy of Right" (1896). This translation must be used cautiously.
Krause, Abriss des Systemes der Philosophie des Rechtes (1828).
Ahrens, Cours de droit naturel (1837, 8 ed. 1892). Twenty-four editions in seven languages. The German 6th edition (Naturrecht, 1870-1871) contains important matter not in the French editions.
Green, Principles of Political Obligation. Lectures delivered in 1879-1880. Reprinted from his Complete Works (1911).
Lorimer, Institutes of Law (2 ed. 1880).
Lasson, Lehrbuch der Rechtsphilosophie (1882).