There should be some basic objective qualifications–such as age, citizenship, criminal record–but I suppose you have much more restrictive ones in mind. (University degree? Business experience? Military experience?)
I wasn’t thinking of mechanical credentials, but more the knowledge that the person has the ability to perform the proper function of government. Basically, this comes down to devising a “test” (72 hour takehome, closed-book or something like that
.) I would be quite opposed to a credential-based system that required e.g. a PhD. On occasion, I entertain the idea that possession of a PhD could be an absolute bar to holding governmental power. But that’s only temporary annoyance, not an actual position of mine.
Your points about putting the requirements in the constitution are correct, and above all I believe that a good constitution should articulate the purpose of the document. The fundamental problem in objective law is that the words tend to become a mantra over time, and law is seen as ritual obedience to a set of words rather than as a means of achieving a specific goal. The US constitution does not set forth a clear statement of the purpose of a proper government, and we’re in trouble because of that. So, as has been suggested here (and elsewhere) a number of times, any law should be rigorously held to a specific purpose: the protection of rights.
So the test of the man would be, does this person understand what the government’s monopoly on force is about; will he mandate its use properly? The takehome exam (I don’t really mean that literally) is a means of determining whether the person has the moral character and knowledge needed to implement the stated function of the constitution. Remember too that a proper government, which exists only to protect rights, will not have a division of Traffic and Parking Enforcement, Health and Social Services, Parks Department, Building Codes, Interstate Commerce Commission, The Mint, FDA, IRS, FCC, DEA, ATF and so on. At the domestic level, all you need is the courts (including the manpower to enforce decisions). The qualification most needed there is knowledge of (objective) law.
Appointing a new judge is a significant event (as is removing a disfunctional judge), and you can rightfully ask questions of implementation. My stock answer is that a 2/3 supermajority should be required to change the makeup of the courts, and that all deliberations must be carried out with explicit reference to the fundamental principles of the constitution. The “initial bootstrap” aspect of the system would basically be however we actually get a laissez-faire capitalist constitution in the first place.
The basic requirement, that government exists solely to protect the rights of man, will not become obsolete over time. The fundamental requirement is that a government official recognize that function and respect it, and if you can’t find someone who can satisfy that requirement, we’re all scrod. As for the problem of selecting the best candidate given two or more equally capable candidates, well, people manage to decide (the “arbitrary decision” problem exists no matter what system you use).