Written Constitutions, with exception is generally rigid and Unwritten Constitution is mostly flexible. Hence, we shall examine merits and demerits of Rigid and Written Constitution on the one hand and those of Flexible and Unwritten Constitution on the other hand.
Merits of Rigid and Written Constitution:
(1) The provisions of a written constitution are stated with clarity and definite words. Thus, there is no ambiguity about the constitutional provisions. It is therefore, clear and definite.
(2) Written constitution is work of constituent bodies, which are especially assigned the task of drafting constitutions. Thus, they take great care and deliberation in this task. For instance, the members of the Constituent Assembly of India thoroughly studied the constitutions of the world and examined their suitability for India. As a result of this our Constitution incorporated the best elements of the U.S. British, Irish, and Canadian Constitutions.
(3) Written and rigid constitutions do not allow the popular whims of dominant legislature to modify easily the provisions of the constitutions. This is necessary, as in democracy, people often become emotional and like to twist the political institutions without any foresight.
(4) Some writes opine that a written and rigid constitution is a guarantee against governmental encroachment of individual rights like life, property, freedom, etc. The Fundamental Rights enshrined in the Indian Constitution with enforcement clause have proved to be a vanguard of individual rights.
(5) Lastly, a written constitution lends element of stability to political institutions arid thus ensures continuity of political tradition and administrative policy.
Demerits of Rigid and Written Constitution:
(1) In the opinion of an America President a 'written constitution is to a country, what a coat too small in size to man.' What is meant by this analogy is that a written constitution attempts to include all political and social ideals of a nation which soon grow out of tune with the passage of time. Unless the process of amendment is relatively easy, the constitution is outmoded.
(2) Often the rigidity of a written constitution proves a liability. Revolutionary changes are the only alternative, when a constitution is too rigid to permit necessary changes. Thus, a rigid constitution is more liable to revolutionary changes than a flexible one. It is said that "the great cause of revolution is that while the nations move forward, constitutions remain standstill."
(3) Where Judiciary acts as the guardian of written constitution, the judges disregard the contemporary social ideals and tend to give a conservative interpretation of the constitution.