EVERY ONCE in a while, the Supreme Court decides a case involving principles so basic you have to wonder why there was ever a controversy. One of these came along Tuesday when the court ruled that in ordinary circumstances the police must get a search warrant before they can legally search a house for a criminal suspect who doesn't live there. The merit of that rule seems so apparent it is hard to understand why two justices dissented and at least three lower courts had ruled otherwise.

Presumably, they did so because the rule will occasionally get in the way of efficient law enforcement. It means that if the police believe a fugitive is hiding in your house, in most situations (except hot pursuit) they must get permission from you or from a judge before they search for him. If you say no and the fugitive excapes while the police are getting a search warrant, law enforcement and the community suffer.

To get around this possibility, some judges decided that, as long as the police have a warrant to arrest someone, they have an automatic right to search any place where they believe he is hiding. The trouble with that is it puts the decision as to whose house is searched solely in the hands of the police -- the precise situation the Fourth Amendment was written to prevent. That amendment says a judge should decide whether the reason the police have for searching a house is sufficient to justify the intrusion on someone's privacy. Without that procedure, cumbersome as it may be, Americans would be no better off than the colonists whose homes were searched by the king's agents anytime there was slightest justification for it.

Maybe the reason the Supreme Court had to decide this particular case is that the diminished respect for privacy in modern society has reduced sensitivities about police intrusion. But surely each citizen is entitled to a place somewhere that is free of official scrutiny. Most people will never object if the police arrive at the door and want to search inside for a fugitive. But for those who do object because they know there is no such person there, the court has simply underlined the message they are free to give to the police: If you want to search my house, go get a warrant from a judge.