What do you mean by preventive detention? Article 22 contains certain safeguards against preventive detention. Explain.

Preventive detention means detention of a person without trial. The object of preventive detention is not to punish a person for having done something but to prevent him from doing it. No offence is proved nor any charge formulated and yet a person is detained because he is likely to commit an act prohibited by law. Parliament has the power to make a law for preventive detention for reasons connected with defence, foreign affairs or the security of India. Parliament and State Legislatures are both entitled to pass a law of preventive detention for reasons connected with the security of State, the maintenance of public order, or the maintenance of supplies and services essential to the community. Safeguards against Preventive Detention Article 22 of the Indian Constitution contains following safeguards against preventive detention: such a person cannot be detained for a longer period than three months unless: An Advisory Board constituted of persons who are or have been or are qualified to be High Court judges has reported, before the expiration of the said period of three months that there is, in its opinion sufficient cause for such detention. Parliament may by law prescribe the maximum period for which any person may in any class or classes of cases be detained under any law providing for preventive detention and the procedure to be followed by an Advisory Board. The authority ordering the detention of a person under the preventive detention law shall: communicate to him, as soon as may be, the grounds on which the order for his detention has been made, and afford him the earliest opportunity of making the representation against the order. It may, however, be noted that while the grounds for making the order are to be supplied, the authority making such order is not bound to disclose those facts which it considers to be against the public interest.