In democratic theory, what is the primary purpose of having a written or unwritten constitution for a country?

Introduction / Context:
Most modern States operate under some form of constitution, whether written in a single document or spread across many laws and conventions. The constitution is often described as the basic law or the fundamental law of the land. This question asks about the core purpose of a constitution in democratic and constitutional systems, which is central to subjects like civics, political science, and Indian polity.

Given Data / Assumptions:

• The question is about the main purpose of a constitution.
• Options mention replacing government, limiting government, giving absolute power, or defining a moral code.
• We assume the general democratic context in which constitutions are framed.
• The focus is on the core function, not on every incidental effect of a constitution.

Concept / Approach:
A constitution sets out the framework of government by defining key institutions such as the legislature, executive, and judiciary. It allocates powers and responsibilities among them and between different levels of government. Equally important, it usually enshrines rights and liberties of citizens and places clear limits on what government may or may not do. In this way, the constitution aims to prevent arbitrary rule and to ensure that public power is exercised according to agreed rules. Therefore, the essential purpose is to define and limit government power, not to grant absolute control or to act as a substitute for government itself.

Step-by-Step Solution:
Step 1: Recognise that the constitution is called the fundamental law that sets up the institutions of government.Step 2: Note that it provides a division of powers, checks and balances, and procedures for making and enforcing laws.Step 3: Observe that many constitutions, including the Constitution of India, contain fundamental rights that protect individuals against misuse of state power.Step 4: Compare this understanding with the options. Only one option mentions both defining government and limiting its powers.Step 5: Reject options that talk about giving absolute power or replacing government entirely, as these conflict with the idea of constitutionalism.Step 6: Select the option that describes the constitution as defining and limiting government power.

Verification / Alternative check:
To verify, consider how courts refer to the constitution. They treat it as a higher law that controls all ordinary laws and executive actions. If a law violates the constitution, courts can declare it invalid. This is only possible because the constitution sets limits on government power. Additionally, constitutional conventions and amendments processes show that the document guides, rather than replaces, the work of governments and legislatures. The presence of fundamental rights and directive principles further confirms that the constitution is designed to protect people from government excess, not to give government unrestricted authority.

Why Other Options Are Wrong:

• To provide a complete substitute for government so that leaders are not needed: Government and its institutions still operate under the constitution; it does not replace them.
• To give the government absolute and unchecked power over citizens: Constitutionalism is about limited government, not unchecked authority.
• To impose a detailed moral and religious code on all people: Some constitutions contain value statements, but their main function is institutional, not purely moral or religious.

Common Pitfalls:
Some learners think that because constitutions are supreme laws, they automatically give the government more power. In reality, they define and organise power and provide mechanisms to check and balance that power. Others assume the constitution is mainly a list of rights or moral principles, ignoring its structural and limiting role. It is helpful to remember that constitutionalism means limited government under a higher law, and that limitation is the central idea behind having a constitution at all.

Final Answer:
The primary purpose of most constitutions is to define the structure of government and limit its powers through basic rules, so that public authority operates within clear legal boundaries.