The decision to adopt a parliamentary system of government in India, with the Prime Minister as the head of the executive, was influenced by several historical, practical, and philosophical considerations. Here’s an examination of the key reasons for this choice, the differences between the parliamentary and presidential systems, and the considerations behind opting for the former.

Key Reasons for Adopting the Parliamentary System
Historical Experience:

British Colonial Rule: India had been governed under a parliamentary system during British colonial rule, especially under the Government of India Act, 1935. Indian leaders were familiar with its workings and had gained experience through legislative councils and provincial governments.
Continuity and Stability: The framers believed that continuity with the existing system would provide stability and facilitate a smoother transition to independence.
Diversity and Pluralism:

Accommodating Diversity: India’s vast diversity in terms of religion, language, culture, and ethnicity required a system that could accommodate and manage this pluralism. The parliamentary system, with its emphasis on collective responsibility and accountability to the legislature, was seen as better suited for this purpose.
Coalition Governments: The parliamentary system’s flexibility in forming coalition governments was viewed as beneficial for a diverse nation like India, allowing for broader representation and inclusive governance.
Accountability and Responsiveness:

Legislative Accountability: The parliamentary system ensures that the executive is accountable to the legislature, with the Prime Minister and the Council of Ministers directly answerable to Parliament. This was seen as a way to ensure more responsive and responsible governance.
No-Confidence Motion: The ability of the Parliament to remove the government through a no-confidence motion was viewed as a crucial check on executive power, ensuring that the government remained accountable to elected representatives.
Fear of Authoritarianism:

Avoiding Concentration of Power: There was a concern that a presidential system, with a single individual holding significant executive power, could lead to authoritarianism. The parliamentary system’s emphasis on collective leadership and periodic accountability was seen as a safeguard against this risk.
Differences Between Parliamentary and Presidential Systems
Head of State and Head of Government:

Parliamentary System: The head of state (President) and the head of government (Prime Minister) are separate. The Prime Minister is the leader of the majority party in the lower house of Parliament and heads the executive branch.
Presidential System: The President is both the head of state and the head of government, directly elected by the people and holding significant executive authority.
Executive Accountability:

Parliamentary System: The executive is accountable to the legislature. The Prime Minister and the Council of Ministers must maintain the confidence of the majority in the lower house of Parliament.
Presidential System: The executive is independent of the legislature. The President is not accountable to the legislature in the same direct way and cannot be easily removed by it.
Separation of Powers:

Parliamentary System: There is a fusion of powers between the executive and the legislature. Members of the executive (ministers) are typically drawn from the legislature.
Presidential System: There is a clear separation of powers. The executive, legislature, and judiciary are distinct and operate independently.
Formation of Government:

Parliamentary System: The government is formed by the majority party or coalition in the legislature. The Prime Minister is usually the leader of the majority party.
Presidential System: The President is elected independently of the legislature and appoints his/her own cabinet.
Considerations Behind the Choice of the Parliamentary System
Existing Institutions and Practices:

The framers recognized that India already had institutions and practices aligned with the parliamentary system, which had been functioning reasonably well under British rule. Transitioning to a completely different system would have posed significant challenges.
Economic and Social Context:

India’s socio-economic conditions, with widespread poverty, illiteracy, and regional disparities, necessitated a system that could provide strong and accountable leadership, while also being flexible and inclusive.
Leadership Preferences:

Key leaders in the Constituent Assembly, including Jawaharlal Nehru and Dr. B.R. Ambedkar, favored the parliamentary system. Nehru, in particular, had a preference for the British model, influenced by his education and political experiences.
Inclusiveness and Representation:

The parliamentary system’s capacity to accommodate a multi-party system and form coalition governments was seen as essential for representing India’s diverse population. This inclusiveness was crucial for maintaining unity and stability in a newly independent nation.
Checks and Balances:

While the presidential system offers a clear separation of powers, the framers believed that the parliamentary system provided effective checks and balances through legislative oversight and the possibility of government change without a prolonged crisis.
Conclusion
The decision to adopt a parliamentary system with the Prime Minister as the head of the executive was based on a careful assessment of India’s historical context, socio-political realities, and the need for stable and accountable governance. The framers drew on the familiar British model, which offered a proven structure for managing a diverse and pluralistic society, while incorporating mechanisms to ensure responsiveness and prevent authoritarianism. This choice has shaped the democratic framework of India, balancing the need for strong leadership with the principles of collective responsibility and legislative accountability.