You are right that the passage cited in this thread, as you say, offers nothing but the federal "neutral magistrates " definitions of "natural rights". The book offers a structure for identifying those rights based upon originalist interpretation of the framers of the Constitution and the 14th Amendment. It comes to sort of a Lochner-era conclusion: since we cannot define the innumerable rights to be protected, they are best protected by striking down laws which take away from one group of people to give to another. For example, welfare takes property from the rich to give to give to the poor. This would be a violation of the right to own property. Only when one person's liberty interest invades another can the government act to prohibit an activity.
Now since I am a conservative, like yourself, and not a libertarian, I was concerned that this leaves government no role in enforcing moral norms. Barnett does believe that a physical invasion of another's liberty must take place in order for the government to regulate an activity. I disagree, but this alone is no reason to completely reject his approach. I simply believe that the government would have the authority to prohibit behavior which was not a physical invasion of another's liberty, but still constitutes a nuisance, e.g. selling drugs, using drugs in public, selling pornography, running a brothel, etc.
Basically, some of the more socially libertarian consequences of his theory are not desireable to conservatives. But that is no reason to trash the theory altogether when, if changed slighty, if offers a more effective alternative to strict constructionalism for conservatives to promote their ideals.
He fails in originalism: "The exceptions here or elsewhere in the constitution, made in favor of particular rights, shall not be so construed as to diminish the just importance of other rights retained by the people; or as to enlarge the powers delegated by the constitution; but either as actual limitations of such powers, or as inserted merely for greater caution."
And the evidence is that the Fourteenth was meant to apply the first eight of the BOR amendments to the states.
And, as we agree, he leaves an undue discretion to the judiciary anyway.
"e.g. selling drugs, using drugs in public, selling pornography, running a brothel, etc. "
-A liberal would instead list: "guns, unemployment, lack of health insurance, unwed homosexuals, etc." (well, I don't know just how a Liberal would phrase them).
The recent spate of research on the Ninth, which Randy's work has encouraged, has been very constructive ( especially since it has led to Levy's excellent "lost history of the ninth").