Constitutions legally codify a government's responsibilities to its people and outline a people's rights that the government must respect. A constitution is usually a written document, however the United Kingdom, New Zealand and Israel are three countries that function politically without a formally written constitutional document. While there are advantages to an uncodified constitution, the disadvantages include no limitations on the legislative body, an unclear division of the powers of government and the possibility of devolution.
One argument for the advantageousness of an uncodified constitution is its flexibility. Unwritten constitutions evolve with a people as their society changes through time. But this flexibility also allows for devolution, such as what has occurred in the United Kingdom. Where once a national assembly represented all member states of the UK, a series of Acts in the late twentieth century resulted in the creation of state assemblies for Scotland, Wales and Ireland. Unwritten constitutions are disadvantageous because they are unable to provide a check on political movements that fragment national unity.
Unclear Division of Powers
Written constitutions clearly establish and define the powers of each branch of government. This means the lawmaking, law-enforcing and ruling bodies of government are separate and distinct from each other. This definition of powers affords the individual branches the power to limit each other so that one branch does not grow to dominate the others. Unwritten constitutions offer no limitations on the unchecked growth of any of the branches of government. A recent trend toward growth of the judicial, or law-enforcing, branch of government leads policy makers in the UK to advocate for a written constitution.
The power of the legislative branch of the government is to make new laws that govern the intricate working of a society. Countries with written constitutions limit the power of this branch because of its inherent potential to make laws that are harmful to a people. Unwritten constitutions have no provision to prevent the creation of laws that could increase inequality within the country, offer protection to the wealthy or limit the basic rights of the poor. An unlimited legislative branch may also be able to levy an inappropriate amount of taxes or send soldiers to war without full support of the people.
Advantages of a Written Constitution
A codified constitution often contains a list of basic rights the government recognises are essential for a society's continued prosperity. While unwritten constitutions offer the advantage of flexibility so they can evolve with a people, written constitutions can also embody this same advantage. Written constitutions that broadly define the rights of a people and the laws of the land can leave room for interpretation by the judicial branch and other officers of the law as the society evolves through time.