Subject
6 free books about natural law, free to read online. Chapter 1 of any book is free, no account needed.
A Discourse Upon the Origin and the Foundation of the Inequality Among Mankind
Jean-Jacques Rousseau
Tradition, Principally with Reference to Mythology and the Law of Nations
John Francis Arundell Arundell of Wardour
The Rights of War and Peace
Hugo Grotius
The Declaration of the Rights of Man and of Citizens
Georg Jellinek
A Discourse on the Study of the Law of Nature and Nations
Sir James Mackintosh
Lectures on the Principles of Political Obligation Reprinted from Green's Philosophical Works, vol. II., with Preface by Bernard Bosanquet
Thomas Hill Green