An interesting chapter from a new book on natural law:
"Public Reason, Secularism, and Natural Law" [pdf]
by Iván Garzón-Vallejo
Francisco José Contreras (ed.) - "The Threads of Natural Law" (Springer Verlag, 2013).
Iván Garzón-Vallejo is Professor at the Faculty of Law and Political Science at the University of La Sabana, Bogota, Colombia.