1. Right is a quality of acts of persons in relationship with other persons, by which we designate what acts and abilities are due in the context of a relationship, such that the privation of that act or ability is considered to be a moral defect (i.e. a human defect, a defect of the person) in breach of a communal relationship.
2. The real basis of rights is the character of the relationships among men: we owe our neighbors, ourselves, our children, our parents, our friends, our enemies, our fellow citizens, our guests, etc., various acts by virtue of these relationships, the nature of which flows from human nature, its inner tendencies, and its necessary orientation toward the common good of a society.
3. Because some relationships precede others in human life, we tend to (rather clumsily) divide rights into two kinds: natural and positive. Natural rights flow from various relationships which precede the organization of any particular state or government within a . For example, the right of a child to receive care from its parents, the right of neighbors to mutual assistance and goodwill, the right of friends to share closely in our joys and sorrows, the right of benefactors to gratitude, etc.
4. Positive rights flow from the positive law of states. The sovereign exists to protect the order of a community and to promote the common good toward which all in that community are ordered. Laws are ordinances of reason for the common good devised by the sovereign and promulgated. They are exercises of political prudence, and therefore mutable, though binding.
5. The division of rights into "natural" and "positive" is clumsy because it suggests that positive rights are not based on nature, which they are. It also suggests that natural rights are somehow fundamental and inalienable, which by and large they are not.
6. Positive rights are granted by laws, promulgated by the appropriate civil authority, for the protection of order and the promotion of the common good. But what constitutes order, what is the common good, depends not on the fiat of the sovereign but on the nature of those governed: on human nature. The basis is the same as natural right, but is mediated by one's relationship with a political community and its sovereign, instead of flowing simply from a direct interpersonal bond.
7. Can rights be revoked? Positive rights very clearly can, since positive law is mutable and depends on the needs which face a community at a particular time. As circumstances change, what was once a right may cease to be one.
8. A more difficult question: can positive law remove someone's "natural" rights? The answer, contra our Jeffersonian impulses, is also "Yes." Natural rights are not, in general, direct and immediate expressions of human nature, but are instead reflective of the demands of a particular species of relationship. In other words: there are rights which in the real order of emergence precede the formation of the state, but which can be reshaped or simply revoked by state intervention without thereby detracting from the perfection of the relationships in question or from the perfection of the individuals involved, in order to more effectively promote the common good.
9. That's a controversial point, but we can see it in action by asking about a more limited case: can natural rights be legitimately revoked on account of the defect (e.g. malice, stupidity) of those attempting to exercise them? Here the answer is also yes. If a person's attempts to exercise a right are likely to do harm, rather than to fulfill the demands of the relationship with which the right is concerned, it is reasonable to prohibit that person's exercise of that right.
10. The broader question stands: what principles ought to govern political prudence regarding the intervention of the state in natural rights and relationships? This is, I think, the right question to ask. Once we start asking this question, we're no longer dealing with Jeffersonian propaganda and its attendant theoretical problems (how does one discover a "human right"?), and can actually make progress.