Warren Albrecht | United States
I believe a good discussion may start in negative and positive rights. A negative right does not enforce the duty on someone else. Duty is usually thought of as an entitlement. A positive right has an entitlement owed. Everybody has a negative right to engage in commerce or trade. But everyone does not have the positive right to impose a duty or force someone else to engage in commerce with you and trade with you.
This is where most libertarians discuss the benefit of free trade. It must be consensual. People in free trade have a contract. I give you three apples and you give me a rope. To have a positive right, someone must have a duty to fulfill for you. The example most widely discussed is the public defender. If you do not have an attorney, one will be provided for you. This means it imposes a duty on someone else to provide and pay for that attorney. The universal agreement is required for a positive right.