In modern parlance, the word right has become more of a colloquialism than a philosophical term. Over usage and misapplication have slowly sapped the meaning from the term. This has problematic ramifications if moral relativism or discussions of semantics are to be avoided. Granted, disputes about the nature and meaning of rights are not novel, but in order to avoid argumentation surrounding purely terminological disparities, defining of expressions is a worthy exercise. Before beginning, a caveat: the intent herein is to determine a definition for a moral right. This concept is distinct from a legal right, a Constitutional right, etc. which may or may not also fit the definition laid out below.
First, a right must be universal. If a concept is to rise to the level of a right, it must apply to all persons in their natural state. Failure on this account either invalidates the claimed right itself or leaves it incumbent on the claimer to indicate by what similarly universal standard are those who are excluded either uniquely undeserving of the right or are actually not human. An exception per the former case may be reasonable in well-defined, specific instances. For example, the mentally ill and children may lack the mental capacity to contract for themselves, an otherwise universal right of adults. In this exception, their right is ignored, but their humanity is preserved as no one need force them to behave in a particular way. Exceptions based on the latter – a subhuman status – necessitate an authoritarian outlook, one in which some are destined to rule others.
A right must also be inexhaustible. This postulate indicates both that a right must be intangible in nature and that rights can only be violated by interactions between persons. That is, there exists no right to police protection because if one posited that there was such a right, and no person on Earth desired to be a police officer, then mankind itself would have become oppressive of your rights. If there was such a right, it would then be moral to force persons to become police officers to satisfy such a right. Similarly, there is no moral right to bread, for if all the grain on Earth perished in a blight then the world itself would have become oppressive of said rights. On the other hand, the right to speak your thoughts, the right to be free from assault and the right to associate with whom you choose are all genuine, moral rights. These rights are inexhaustible and can only be violated by fellow humans.
Finally, a right cannot be commoditized. Rights cannot be quantified and their benefit to the user – though perhaps measurable – is a meaningless calculation. This is because rights are not exchangeable due of the first two postulates. Their universality and inexhaustibility make an exchange of equal rights nonsensical. Rights are not fungible. The worth of a right is of the highest order of subjectivity – its value completely the domain of the person exercising it.