During the few weeks before Ronald Reagan named Gen. Alexander M. Haig Jr. to be his secretary of state, the rumor in knowledgeable circles ran as follows:

"Of course the man's treacherous, but he's familiar with the issues, and besides, there's nobody else."

Now that Haig has been appointed, the rumor has congealed into the received opinion, accepted by partisans on both sides of the argument in the Senate, as to the general's qualifications for an office still associated with the hope of honor. Haig's critics object to him on ethical grounds, saying his flaws of character compromise his undoubted capacity for bureaucratic intrigue. The general's admirers, among them Richard M. Nixon, concede the ruthless and single-minded ambition of their man but applaud these attibutes as virtues -- saying, in effect, that the world has become so dangerous a place that the United States requires the services as a villian. "The meanest, toughest, most ambitious s.o.b. I ever knew," Nixon has called Haig, "but he'll make a hell of a secretary of state."

The agreement on the general's character raises the unhappier question as to what kind of country -- and what kind of president -- would think it necessary to employ Alexander M. Haig Jr. What is meant by the reasoning that there is "nobody else" to be secretary of state?

In a country of 225 million people, among whom at least several thousand possess a knowledge of international politics and diplomatic history, obviously it is absurd to say that only Haig (or perhaps one or two others of Reagan's Republican acquaintances) could perform duties of the secretary of state. The lack of candidates bespeaks a lack of candor about what the task entails.

Haig's qualities define the accomplished courtier. He is eager, smiling, willing to deny or distort the truth for an expedient purpose, loyal to power in whatever person or institution it makes itself manifest, as cruel or compassionate as the circumstances might warrant. Casting himself in the role of the indispensable valet or aide-de-camp (first for Gen. Douglas MacArthur, then for patrons as different as Robert McNamara, Henry Kissinger and Richard Nixon), Haig made his career by saying to a succession of masters, "Make of me what you want; I am what you want me to be." The general proved himself useful, a silent and dependable man who could be relied upon to tap a telephone or arrange a bombing in Cambodia.

Nothing in the general's record indicates the qualities of a public man accustomed to making his own decisions or writing his own speeches. He gives a poor speech, the banality of the test unrelieved by any talent for humor or eloquence. His manner betrays a cold egoism as well as the court chamberlain's habitual air of contempt -- for his employer, for everybody else in the throne room, for the rabble beyond the gates.

Who would trust a man so schooled in the art of subservice to formulate a policy? As secretary of state, how will the general excuse and justify himself? On whom will he blame his failures?

The explanation of this appointment arises from Reagan's ignorance of foreign affairs and his lack of enthusiasm for anything unpleasant. "Society," said Justice Holmes, "is based on the death of men," and Haig's military education presumbably has taught him to look impassively upon the spectacle of human suffering. Since the end of World War II, the United States has raised up two generations of civilian officials who flatter themselves on their mauve sensitivity -- to the environment, to human rights, to the death of newts and whales. The pale cast of good intentions inhibits their appetite for action; on the brink of the abyss it occurs to them that their advice might prove fatal. Thus their wish for a Praetorian Guard.

For 15 years Haig has been close enough to power to remark the weakness, the vanity and the corruption of his nominal overloads. Maybe it is easier to pay court to men one despises, and it is understandable that Haig, having seen with what little wisdom the world is governed, should have formed an excessive opionion of his own. What remains less understandable is the way the political and intellectual gentry fawn over what they imagine to be the general's strength, the general's patriotism, the general's self-discipline, the general's moral beauty.

Nothing in the soothing charm of Ronald Reagan's voice indicates that he means to do anything other than preside, in the affable and ceremonial way of a retired chairman of the board, over the cruelties of government. Like the later Roman emperors, who allowed the business of the state to fall into the hands of eunuchs, he confers the powers of office on the gamekeeper in order that he might not be offended by the sight of blood.