Murray Rothbard, in his book Ethics of Liberty, wrote:
It is not the intention of this book to expound or defend at length the philosophy of natural law, or to elaborate a natural-law ethic for the personal morality of man. The intention is to set forth a social ethic of liberty, i.e., to elaborate that subset of the natural law that develops the concept of natural rights, and that deals with the proper sphere of “politics,” i.e., with violence and non-violence as modes of interpersonal relations. In short, to set forth a political philosophy of liberty.
In our view the major task of “political science” or better, “political philosophy” is to construct the edifice of natural law pertinent to the political scene.
Rothbard’s distinction between political philosophy and the “personal morality of man” is important. As far as I know, Rothbard actually never wrote on morality, only political ethics. As a Christian, the moral standard of conduct to which I adhere is found in the Bible.
What about his use of “natural law?” I’ve discussed before the problem of deriving an “ought” from an “is.” Thus, natural law as it has been historically developed is, in my estimation, flawed. But insofar as natural law might refer (it doesn’t usually) to ethics that are created by God, not man, we are in agreement with Rothbard. Personally, I think the phrase natural law is too Thomist. But law is certainly not artificial. Perhaps we should call it supernatural. At any rate, we know what Rothbard means and whether or not we think his empiricism justifies it, we can agree ethics do not come from the conventions of society.
But beyond the issue of moral standard, which we find in the Bible, the role of political philosophy is to investigate the proper use of violence and coercion. That the criminal engages in an improper use of coercion is what makes him a criminal. The political theory of libertarianism (in the Rothbardian and Reformed Libertarian strain) is that criminals, those in society who are to be punished under the law, are those who initiate coercion against the person or property of another individual. This principle includes things like theft, murder, and breach of contract.
This also means that there are certain sins which conservatives often rightly consider sins but wrongly see as criminal. For instance, prostitution. This provides an excellent opportunity to discuss a difficult issue for many Christian conservatives. Typically, Conservatives ask the Christian libertarian: how can you possibly think that Prostitution is fine to exist in society? And the Christian libertarian should respond: we don’t think it is fine, we just don’t think using the physical power of the State is the means by which we should seek to end prostitution. Well then what means do we have, without force? Well, we have safe houses and non profits and churches and prayer and evangelistic teams and the life changing power of the Gospel! Social ills cannot be addressed by the use of the State because the external practice of sin (prostitution) is not the root of the problem. We are dealing with heart issues. We are dealing with souls that hate God. The prostitute, more often then not, is a victim, and needs to be cared for, dealt with patiently and mercifully.
That sexual activity outside of marriage is a sin and abomination to God is agreed. But this is not the topic of debate.
I think that many Christians do not understand what it means for something to be “illegal.” And thus they do not understand what it means when the Christian libertarian says something immoral should be “legal.” All we are referring to, once we honestly consider the situation, is that “illegal” means that the use of aggression is justified against a given activity and “legal” means that the use of aggression is not justified to prevent it.
My fellow Christian conservatives, do you really think that Christ wants us to advocate aggression against the prostitute? If you answer that prostitution has harmful effects on society and God does not approve of it, please understand: I completely agree with you but will remind you that you have not answered the question.
Are not the Gospel and the Holy Spirit more impactful than the State? The State has been a dismal failure in eradicating sin. Perhaps Christians have expected too much of it.