For all the controversy that has surrounded him, Sir Stephen House is right in one regard.

Look beyond the arguments over rules, philosophies, statistics and procedures. One thing can be said for certain about the police and stop-and-search: "When you do stop and search it is not about what you do; it is about how you do it."

In a society that depends on policing by consent, that is the very heart of the matter. If officers are to keep us safe from knives, to take a notorious example, it is inevitable that people will be stopped and searched. It is not inevitable that the police should become overbearing, that the innocent should be harassed, that children should be involved, or that the law should be vague.

All of this is easier to propose than enact. To those who demand statutory searches accompanied by the full ritual of rights and stated police suspicions, Sir Stephen offers a warning. If English experience is anything to go by, he argues, what seem to be protections can lead easily to antagonism. Against the supposed informality of consensual stop-and-searches, in the prevailing Scottish manner, there is the risk of confrontation.

The Chief Constable's argument is reasonable, but only as far as it goes. Political arguments over stop-and-search have arisen precisely because consensual informality seems to obey too few rules. Scottish officers, as we have discovered, are vague about the law governing their searches. A lack of definition has led, among other things, to a statistical mess resulting in absurdly inflated figures. But it has also been a cause of public concern over the very use of the procedure.

The first thing required from the Scottish Government review being led by the human rights lawyers John Scott, therefore, is some degree of clarity. Those we pay to enforce the law must surely be given a clear understanding of the law governing their actions. Trust depends on it, and the police depend on trust.

It seems equally obvious that a balance needs to be struck between two competing views of how officers can and should behave. Sir Stephen, though more than willing to operate as required, might regret the loss of consensual stop-and-search. Others contend that there is no reason why searches based on formal "reasonable grounds", in the English manner, should not also be respectful and friendly.

Much of this will depend on police training and attitudes. It is easy to pontificate about those, less easy to say how officers are supposed to remain genial at all times. In fraught and sometimes dangerous situations the police do what needs to be done. They should be sure, nevertheless, of their legal ground and be clear about the behaviour expected from them. Their superiors should be equally certain officers understand what that means.

It seems inevitable that some sort of statutory basis will have to be given to stop-and-search. The "consensual" approach is a kind of fiction, after all, one that ends the instant co-operation is no longer forthcoming. Nevertheless, reform need not mean the wholesale adoption of an English approach that has led, too often, to distrust and rancour.

The best of both worlds, if it could be achieved, would satisfy most people in Scotland. It is a tall order, but the challenge cannot be evaded.