William French Smith, the handsome and courtly Californian who served as Ronald Reagan's first attorney general, turned up in town recently to get a load off his mind. He told a House subcommittee that it's high time to get rid of ''independent counsels'' who get appointed under the Ethics in Government Act of 1978. He is absolutely right.

The 1978 act, if you recall, was adopted during the spasms of morality that swept over Congress in the wake of the Watergate affair. Among the act's unfortunate provisions was a section requiring the appointment of a special prosecutor -- later retitled an independent counsel -- whenever allegations of criminal wrongdoing are made against a government official. The act expires next year. Smith's advice is to let it go.

In one sweeping sentence he set forth his objections: ''In my opinion this legislation has not served the ends of justice, is cruel and devastating in its application to individuals -- falsely destroying reputations and requiring the incurring of great personal costs; has applied artificial standards often unrelated to culpability, and to that extent has prevented the use of normal standards of prosecutorial discretion; has been used more for political purposes and media appetite than to achieve justice; has been a nightmare to administer, and has caused a needless and substantial waste of taxpayers' money.''

Every word of that is true. The first invocation of the law, if memory serves, was against Hamilton Jordan, a top-ranking aide to President Carter. This was in November 1979, when a flimsy charge was made that a year earlier Jordan had tried a snort of cocaine at a New York discothe`que.

Under sensible procedures, this dubious allegation would have been turned over to the Department of Justice. The department would have looked into the matter, found it baseless, and gone about its business. But, no. Under this portentous act, a special prosecutor, Arthur H. Cristy, had to be appointed. It wasn't until the following May that Cristy's investigation cleared Jordan. Meanwhile Jordan had endured six months of undeserved hell.

A few months later, in September 1980, a similar allegation was raised against White House aide Tim Kraft. He was to manage Carter's 1980 campaign, but the unfounded charge put him on the sidelines. A special prosecutor cleared him in March 1981.

Edwin Meese, while he was still at Reagan's White House, before he became attorney general succeeding Smith, went through an anguishing ordeal. He was accused of using his influence to get federal jobs for people who had provided financial assistance to him. If the charges had been true, he would have been subject to indictment. But the charges were manifestly untrue. Special counsel Jacob A. Stein came to that obvious conclusion after months of investigation. The probe cost the taxpayers $721,000 in Meese's legal fees alone. Now Meese is under investigation again, but there is no reason why the Department of Justice itself could not handle the matter.

By my inexact count, we are now in the midst of the ninth costly investigation by an independent counsel. In addition to the charges against Jordan, Kraft and Meese, allegations against Michael Deaver and Ray Donovan have been probed. None of these found any violation of federal law. (Deaver was indicted, but not for any of the charges that triggered his investigation.) Special counsel Lawrence Walsh now holds a brief for the whole of the Iran-contra affair. An investigation of Lyn Nofziger's lobbying is incomplete. Two other investigations involve unidentified persons in the Justice Department.

In brief, Smith told the House subcommittee, this ''cumbersome and expensive process so far has damaged reputations but produced little else.'' The rigid provisions of the law require that special investigations take precedence over any other matters that might occupy the FBI and the Department of Justice. The act makes no distinction between trivial allegations and serious allegations. Independent counsels, who are appointed by a panel of the Court of Appeals for the District of Columbia, are subject to none of the checks and balances that normally govern prosecutorial discretion.

Smith did not get into the constitutionality of the act, but he has publicly expressed his doubts many times. Under the Constitution it is the duty of the executive, not the judiciary, to enforce federal laws. Toward this end a president appoints U.S. attorneys. The Ethics Act violates this principle of separation of powers. That issue to one side, as Smith said, the ''independent counsel'' provision is just plain bad law. It ought to be abandoned.