The evolution of the doctrines "Procedure Established by Law" and "Due Process of Law" in the Indian constitutional framework reflects a nuanced approach towards safeguarding individual rights and liberties within the legal system. This evolution can be understood through historical context, judicial interpretations, and landmark cases that have shaped the understanding and application of these doctrines.

Historically, the choice between "Due Process of Law" and "Procedure Established by Law" in India's constitutional development traces back to discussions during the drafting of the constitution. The Constituent Assembly, influenced by concerns raised by legal experts such as Sir B.N. Rau and insights from international legal frameworks, initially adopted the concept of "Procedure Established by Law" to prevent judicial overreach and uphold parliamentary supremacy.

However, the interpretation and application of these doctrines took a significant turn with judicial pronouncements and evolving legal principles. One of the pivotal moments was the case of Maneka Gandhi vs Union of India (1978), where the Supreme Court of India expanded the scope of Article 21 to include principles of fairness, justice, and reasonableness. This landmark judgment essentially equated the phrase "procedure established by law" with the broader concept of "due process of law."

The Court's decision in Maneka Gandhi's case marked a shift towards a more liberal interpretation of individual rights, emphasizing that a procedure established by law must not be arbitrary, fanciful, or oppressive. This interpretation elevated the importance of principles of natural justice, ensuring that legal procedures are fair, just, and in line with constitutional values.

Subsequent judicial pronouncements and rulings further strengthened the protection of individual rights under Article 21. For instance, in cases like Selvi v State of Karnataka, the Court struck down certain investigative techniques that infringed upon the right against self-incrimination, demonstrating a commitment to ensuring fair trial procedures.

The Indian judiciary's adoption of a liberal interpretation post-1978 effectively blurred the distinction between "Procedure Established by Law" and "Due Process of Law." The emphasis shifted from a mere procedural adherence to laws to a substantive evaluation of the fairness and reasonableness of legal procedures.

In essence, India now follows a doctrine that incorporates elements of both "Procedure Established by Law" and "Due Process of Law." While the constitution explicitly mentions the former, judicial interpretations and judgments have imbued it with the essence of due process, ensuring that individual rights are protected not just procedurally but also substantively. This evolution reflects a maturation of India's legal system in balancing legislative authority with constitutional rights, thereby providing a robust framework for safeguarding individual liberties.