The arrest of Rabbi Dov Lior two days ago is a controversial act that has aroused worrisome reactions. Those who favor freedom of expression will of course find it difficult to accept as self evident the arrest of a person, any person, for things that he said or wrote. An open and liberal democratic society is not tested by its support for speakers or writers of texts of which it approves, but by providing an opportunity to say harmful things, as infuriating and subversive as they may be, about it and even against it.

From the start, therefore, the investigation against Rabbi Yitzhak Shapira, author of the inflammatory work "The King's Torah," which among other things preaches in favor of killing Arab infants - and the investigations against the rabbis who wrote their "endorsement," in other words a kind of halakhic seal, is proceeding on thin ice.

It may have been wiser for the police and the Shin Bet security services to decide to allow these inciters to continue to trade in their dubious merchandise, and at the same time to continue to keep tabs on the practical results of their words, using the methods permitted in a democracy. But from the moment that the police decided to summon Rabbi Dov Lior to an investigation, he should have reported, even if he is firmly opposed to doing so, and taken advantage of every legitimate way of protesting against the claims against him.

Rabbi Lior is a central figure among the religious right, the rabbi of a settlement (Kiryat Arba) and the head of a hesder yeshiva (which combines Torah study and army service), and is therefore obligated to be especially meticulous about observing the official rules and demonstrating exemplary civic behavior. But in spite of the fact that all the possible ways of protest are open to him, and the media are attentive to his every word, he preferred to wage another campaign of incitement against the law-enforcement authorities, which ignited a dangerous fire among his students and his admirers.

The battle being led by Lior against the state and its institutions is a consistent and continuing one. Just as he praised Baruch Goldstein after the massacre in the Cave of the Patriarchs in Hebron in 1994, and changed the wording of the Prayer for the Welfare of the State after the disengagement from Gaza, he is now inciting against the rule of law. Freedom of expression must be strictly maintained, but Rabbi Lior should be dismissed from all his positions. Democracy is not supposed to employ fomenters of riots who are trying to crush it in the name of halakha.