For the third time in 13 months, civil servants throughout the government were notified last week that they are "inessential" and should "suspend operations." The entire federal government has again been held hostage to a combination of congressional financial irresponsibility and executive stubbornness.

These periodic guerrilla attacks on the government's ability to operate, directed by the nation's highest elected officials, have two obvious effects: they squander millions of dollars, mostly in wasted salaries, and they wreck morale in the civil service.

According to the House Civil Service subcommittee, the cost of the shutdown in November 1981 was some $82 million. That's about the same amount slashed from the budget of the Legal Services Corporation. And it's pure waste.

The cost in civil service morale is hard to measure but just as important. Imagine how you'd feel if your employer sent you a notice every four months saying that your job was "inessential." Imagine being told to stay on the job but to stop working. That's exactly what's been happening throughout the government.

Everyone knows there are intractable problems with the civil service. Few bureaucrats have an immediate stake in the quality of decisions they make, or the speed with which they make them. Responsibility is easily evaded. Incompetents are nearly impossible to fire -- or else the firing process is so absurdly protracted and expensive that few managers are willing to invest the time and money needed to do it.

An assistant attorney general told me recently that it takes two years just to get rid of one incompetent employee in the Justice Department. So the civil service is flabby and sclerotic. This is not only expensive, it also depresses the qualified and energetic people who work in it.

Increasingly there is recognition that these problems are common to all large bureaucracies, private as well as public. Big business as well as big government suffers from them.

But there remain two cardinal differences between private and public bureaucracies in this country. One of those differences is part of the bedrock of a free society and the other is one of its glories. The first difference is that the public bureaucracy, the civil service, pursues business prescribed for it by an elected legislature, not by private citizens seeking private gain. It is a res publica, a public thing.

The second difference is that many citizens believe in that business and are willing to pursue it even at financial sacrifice to themselves. Some do so temporarily, seeking advancement or long-term financial advantage through the "revolving door." But a surprisingly large number pursue the public business because they believe in it and want to make a living pursuing public, unselfish ends.

Among these people, some have a political agenda or a personal stake in programs whose survival is now in question. Most, however, are professionals who do as directed if given a modest amount of encouragement. These are the people who make the behemoth work on a daily basis.

If you doubt that such people abound, consider this: The latest furlough memorandum circulated in the Justice Department stated: "during the furlough, you will not be permitted to serve as an unpaid volunteer but must remain away from your work place . . . . " Numerous volunteers would otherwise work.

Thus we have the ultimate irony of the situation: a Republican executive telling the civil servants, whom it generally decries as lazy and irresponsible, that they are forbidden to serve as volunteers.

Ronald Reagan was elected to do his job, and he has the right -- perhaps the duty -- to seek to reduce the percentage of GNP represented by the federal budget. Sage heads wish him success. He also has the right to alter the government in accordance with his announced principles, and his appointees are certainly trying.

Interior Secretary James Watt doesn't much like the laws administered by the Interior Department. Education Secretary Terrel Bell certainly doesn't care much about the existence of the Education Department, and Secretary James Edwards had a similar opinion of the Energy Department. Few think environmental protection is high on EPA Administrator Anne Gorsuch's agenda. And there are quite a few antitrust laws that Assistant Attorney General William Baxter is known to abhor. (Oblivious to his obligations as a law enforcement official as well as an intellectual and an honest man, all of which he is, he has even stated his refusal to enforce some of them).

Let it be acknowledged that well-intentioned people have differences of opinion about all these organs of government and the laws they enforce. Yet to alter the government by holding its existence hostage is either childish or bloody-minded, or both. Every citizen's interest is harmed. The British would call this a constitutional crisis, and so it is; because it threatens to bring the entire government to a halt.

The president, Congress and all citizens have a vital interest in ensuring that the government works and that the civil service is as efficient, well motivated and highly qualified as possible. Shutting down the government subverts those goals. To have done so three times in 13 months is a disgrace both to a Congress that can't pass orderly budgets and appropriations, and to a president who seems to enjoy bashing the civil service at every opportunity.