THE announcement of Richard Thornburgh's selection as United States attorney general is good news. It is heartening that, unlike those of too many who have held the job, his qualifications go beyond mere friendship with the president. A former head of the Justice Department's criminal division, he has extensive experience as an effective prosecutor in state and federal cases. He has a reputation for integrity and for working precisely and methodically.
And unlike many other Cabinet appointees, Mr. Thornburgh has had experience in elective office - as a popular two-term governor of Pennsylvania. He is widely expected to be a shoo-in for confirmation.
Since leaving office in 1986, he has been director of the Institute of Politics at Harvard University's Kennedy School of Government. There he has been involved in trying to bridge the gap between the worlds of academia and politics and preaching the virtues of elective office to those put off by ``the mystique of politics.'' During the primary season, Thornburgh has quietly kept in touch with the various Republican campaigns.
Given the way Mr. Meese's continued tenure in office had become a political liability for George Bush on the campaign trail, it is significant that President Reagan has nominated to fill the attorney general's post a man mentioned as a possible Bush running mate.
In any case, it will surely boost morale at the Justice Department to have a successor named for Edwin Meese, who is to depart next month.
Even more important, Thornburgh offers the promise of a fresh look at the Justice Department - an end to the narrow agenda the Reagan administration had tried to impose under Mr. Meese, and the prospect for the transition to a more socially inclusive and evenhanded Justice Department if Mr. Bush wins.
It is tempting to see this as a caretaker appointment. But the attorney general is the nation's chief law enforcer, and whoever holds the post can set a tone and a standard for the administration of justice, which should know no change from one presidency to another.