Article 21 is the absolute crown jewel of fundamental rights: "No person shall be deprived of his life or personal liberty except according to procedure established by law."
The judicial interpretation of this single sentence has undergone a massive, historic evolution.
1. The Gopalan Era (Restricted View)
In A.K. Gopalan v. State of Madras (1950), the Supreme Court took a narrow, literal approach. The Court held that "procedure established by law" meant any procedure passed by a legislature, even if completely unfair. Personal liberty meant only freedom from physical confinement of the body.
2. The Maneka Gandhi Revolution (Expansive View)
In Maneka Gandhi v. Union of India (1978), the Court completely reversed its view, establishing that:
- The procedure depriving a person of life or liberty must be "fair, just, and reasonable"—and not arbitrary, fanciful, or oppressive.
- The Court effectively integrated the American concept of Substantive Due Process into Article 21.
- "Life" is not mere animal existence, but includes the right to live with human dignity.
3. Implied Rights Read Into Article 21
Using the Maneka Gandhi framework, the Supreme Court has declared several rights as part of Article 21:
- Right to Privacy: Declared a fundamental right by a 9-judge bench in K.S. Puttaswamy v. Union of India (2017).
- Right to Education: Article 21-A added by the 86th Amendment, guaranteeing free education for children aged 6-14.
- Right to a Clean Environment: Free from pollution (M.C. Mehta v. Union of India).
- Right to Free Legal Aid: Essential for fair trial (M.H. Hoskot v. State of Maharashtra).