No enforcement, no duty. No enforcement, no right. There are no natural rights. There are no natural duties. Duties entail privileges to enforce.
Natural duties are possible, despite nonenforcement.
Natural rights are possible, despite nonenforcement. Moral properties and relations pertain to individuals and individuals only. No moral judgment is meaningful unless it is equivalent to a proposition about individuals. 8 Duty is a relation. The only duties that exist hold between individuals or an individual and himself or herself.