Alex Salmond suggests that a Scottish constitution could cover issues like weapons of mass destruction, homelessness and free education. I don’t resile from the policies, but they are not constitutional issues – once they are included, there is nowhere to stop. What should be left out – biodiversity, climate change, sustainability, EU membership, pensions, marriage, health care? When the abortive European constitution was under discussion, I wrote this:
A constitution is a foundational statement. It needs to be communicative, transparent, and justiciable. Every constitution needs to set out the basic institutional framework. It needs to state primary legal rules – rules of recognition, change and adjudication. It should probably state fundamental principles, like the Bill of Rights in the US constitution. But it should not include policy. Instead of confining itself to constitutional issues, the “constitutional treaty” sought both to consolidate the content of previous treaties and to include substantial elements of previously agreed policy – issues like the environment, agriculture and fisheries, and commercial rules. However important these may be, they are not constitutional principles; and whatever the merits of the policies may be, it is very questionable whether the policy which is appropriate now should be expected to be appropriate a hundred years from now.
My colleague Paul Arnell has argued against a constitution, giving the example of the right to bear arms in the USA as bad law that has proved impossible to change. That seems to me an argument against the inclusion of substantive law, rather than an objection to all constitutions. A constitution should confine itself to principles and the institutional framework. It should not include matters of policy or substantive law. And it must be short.