Deutsche Welle: The discussion of the PRISM data collection program has sparked a new debate on the right to security and the right to freedom. German Interior Minister Hans-Peter Friedrich calls security a "super right." Is there such a thing as a basic right that is superior to other basic rights?

Horst Dreier: No, there is no such thing. On the contrary: in the framework of constitutional legal theory, there has always been the prevailing opinion that there is no hierarchy of basic rights. The only exception one could possibly make is human dignity, that is, if we regard it as a basic right and not as an objective constitutional principle. Human dignity is in fact superior because it is embedded in article 79, paragraph 3 of the German Basic Law, in what is known as the Eternity Clause.

How can one strike a balance between contradictory basic rights? At the moment, many politicians say, we need surveillance to a certain extent to ensure citizens' safety - and that is more important than protecting privacy.

In general, all I can say is: it is important to weigh all of the pros and cons and then to strike an adequate balance. Of course, that doesn't result in a clear conclusion, it just points out the task at hand. I think we are dealing with an entirely different aspect that, however, should not be expressed by using the unfortunate term of a "super right." That is to say, security has always been the state's duty. Establishing security, or domestic and external peace, is the basic, the core legitimization for the existence of the state - we have known that as a fact since Thomas Hobbes, who established the modern-day theory of the state.

Does that mean the state is allowed to curtail its citizens' basic rights to do justice to its function?

Yes, that is standard legal procedure. If you look at the development of state and constitutional law in Germany, the point is that for the past decades, we have been able to cover this ancient public responsibility of security with the duties of protection anchored in the Basic Law. But it is not a basic right in opposition to others. We must ask ourselves: What must and what can the government do to protect a citizen from violations by another citizen and to what extent is it allowed to infringe upon the privacy of the other?

Let me give you an example with regard to the current discussion: If a private German company had conducted the surveillance, and not the US National Security Agency NSA, it would be abundantly clear that such a violation of innumerable citizens' right to freedom, privacy and informal self-determination by a private agency would be absolutely unacceptable and absolutely inadmissible. Introducing new norms would not be necessary to prevent such activity; one would merely have to apply the existing ones.

But if the state does interfere in the citizens' fundamental rights - is there a rule of thumb when a judge's approval becomes necessary?

From the point of view of constitutional law, that is relatively easy: you need a legal basis for every intrusion into a citizen's privacy and his basic rights. And the intrusion must be proportionate, which means, it must be essential and may not affect the privacy of the individual excessively. As I said, imagine a private firm were doing this in Germany. We now have the interesting situation that it is a foreign government! Constitutional lawyers will ask themselves the fascinating and by no means settled question: do a state's fundamental duties of protection take effect in relation to other states as well? Here, we may be treading on interesting new ground.

So, if the US violates German basic right,- the legal consequences are not clear?

Not that I know of. If I understand correctly what the Americans are saying, their attitude is: we are not allowed to just monitor our own citizens without control. But foreigners? Anytime and with no limits! That can't really be right; at least it is not along the lines of the German Basic Law.

Should Germany defend itself more decidedly against foreign surveillance in order to fulfill its duty of protection?

I would say so! In any case, one can not put the matter to rest simply by pointing out these are actions not taken by the German government, but by foreign authorities. The exciting question is: to what extent are the state's duties of protection activated if the infringements - violations of constitutional rights such as comprehensive illegal wiretapping - aren't instigated by other citizens, but by other states? Admittedly, these duties of protection are structured in a way that the state has a relative broad scope of discretion. But I feel it is evident that the state must in some manner fulfill these duties of protection and cannot remain completely passive.

Horst Dreier teaches the philosophy of law and constitutional and administrative law at the University of Würzburg. He's the editor of a three-volume commentary on the German Basic Law.