Article 21 reads as:
“No person shall be deprived of his life or personal liberty except according to a procedure established by law.”
What are the meaning of life and personal liberty, this question came before the Supreme Court first time in the case of A.K.GOPALAN Vs THE STATE OF MADRAS, 1950? In this case, the petitioner challenged his detention on various grounds. The Supreme Court held that procedure established by law means- enacted piece of law. It does not mean due process of law. If there is a procedure, a person can be deprived of his life or personal liberty. Thus Supreme Court made the literal interpretation in this case.
But in MANEKA GANDHI Vs UNION OF INDIA, 1978- the Supreme Court overruled its previous decision. In this case the Supreme Court held that procedure established by law means due process of law. The procedure must contain the principle of Natural Justice. It must be just, fair and reasonable. If a procedure is not just, fair and reasonable it is not a procedure at all.
In this case Supreme Court also widened the meaning of life. According to Supreme Court life is not mere an animal existence. All the amenities are included in the meaning of Life. After the Maneka Gandhi case various rights have been included in the right to life. For example- Right to pollution free environment, right to health, right to sleep, right to shelter , right to livelihood etc. have been included in Right to Life under Article 21 of the Indian Constitution.