"We don't have a chief of staff," the young Iranian presidential aide explained. "Everybody is a Hamilton Jordan here."

In 16 months of Iranian revolution, some method to the madness that is the Iranian state has sprung up. But the methods are ad hoc. It is government by improvisation, policy by ad lib. There is no clear strategy for achieving specific political or economic goals, but rather a tendency to drift, to vacillate and to opt for expediency.

In some ways, the policy-making of President Abol Hassan Bani-Sadr and the Carter administration may have more in common than either would care to admit. They have shown similar characteristics in a number of instances, including their dealings with each other.

In fact, according to one Iranian official, a model of the Carter White House organization was among several studied when the Iranians were setting up their presidency following Bani-Sadr's landslide election victory Jan. 25.

The problems of setting up new institutions have been among the many difficulties faced by Iran's new leaders since the February 1979 revolution. Most of these institutions have arisen more or less spontaneously, and most are controlled by the Moslem clergy.

By and large, the institutionalization of the revolution has meant the institutionalization of clerical power in Iran. The loser in this process is Bani-Sadr, who risks being reduced to figurehead status by his hard-line clerical rivals.

How well the mullahs are able to anchor themselves in Iran's institutions will determine the outcome of the current power struggle and the country's future.

So far the major wild card in the consolidation of power by the mullahs has been the presidency. Practically by default, it has become the main counterweight to unbridled clerical power in Iran.

But it is an ineffective counter-weight. One reason is that under Bani-Sadr, the presidency seems to be institutionalizing disorganization, while the mullahs gather power.

Illustrating this is the present's philosophy of "nonconcentation of power," which entails creating a society based loosely on individualistic emulation of Ayatollah Ruhollah Khomeini, known by his followers as "the imam."

"Every person in Islamic society should become an imam by himself," presidntial aide Mohammed Hassan Pir Hosseini explained enthusiastically. "There should be 35 million Imam Khomeinis."

Another reason for Bani-Sadr's inefficacy is that although he won the presidency with 75 percent of the vote in January, Iran's new Islamic constitutiion is fuzzy about who is supposed to wield top executive power, the president or a yet-to-be-named prime minister.

The clerics of the Islamic Republican Party, led by Ayatollah Mohammed Beheshti, insist in their party newspaper that the 270-seat assembly is the "highest and most powerful legal decision-making body of the country." The party lost out to Bani-Sadr in the presidential vote but won clear control of parliament in the later legislative elections.

In an efort to reinforce their power in the parliament -- where they hold 130 of the 241 seats so far decided -- the Islamic Republican clerics have been jockeying with Bani-Sadr on choosing the new prime minister. They managed to scuttle his first attempt to install his own man before the parliament convened May 28 in an inaugural session.

The decline of Bani-Sadr's power in part reflects his lack of effective party organization beneath him, which may in turn stem from his own philosophy of "decentralization."

That did not matter so much in the presidential election, which turned into a contest of personalities, but it buried him in the parliamentary run-offs, which featured long lists of obscure candidates.

Also undermining Bani-Sadr constitutionally is the Islamic republic's ill-defined concept of velayat-e-faghih, which in effect assigns supreme power to Khomeini or, in his absence, to one or more popularly recognized religious leaders.

In seeking of the presidency, Bani-Sadr benefited from Khomeini's unexplained order banning clergymen from the race and the switching of Islamic Republican Party candidates in midcampaign.

Bani-Sadr also seemed to have the best of both words in Iranian politics: he attracted Khomeini supporters by identifying himself closely in his campaign with the ayatollah, but he got a share of the antimullah vote of disaffected Iranians because of his credentials as a Western-educated, secular economist.

That Bani-Sadr has been unable to translate his popular mandate into strong leadership in part shows the Islamic Republican Party's behind-the-scenes strength, which relies at the grass-roots level on the country's vast mosque network.

Besides the parliament and the Revolutionary Council that legislators are supposed to replace, clercial hardliners, most of them loyal to the Islamic Republican Party, effectively control two important institutions: the revolutionary courts that dispense the country's Islamic justice and the Revolutionary Guards, the elite fighting force loyal to Khomeini.

The party's men also dominate the hundreds of revolutionary komitehs, or committees, which still perform many police functions throughout the country more than a year after their spontaneous formation.

They also control the national radio-television network, the Voice and Vision of the Islamic Republic. In addition, clerics retain key positions in the wealthy Poor People's Foundation, formally charged with administering the property of toppled officials and providing homes to the poor.

Other examples of the entrenchment of the "mullah system" are such bodies as the Center for the Abolition of Sin, a sort of Khomeini-inspired vice squad, and the Marriage Bureau, in which volunteers for matrimony are paired on the basis of questionaries they fill out in the Islamic Republic's version of "The Dating Game," played here for keeps.

Aside from the mullahs' own efforts to extend and institutionalize their influence, Bani-Sadr's plummeting authority also stems from his own short-comings. He is not, in the view of Tehran analysts, a man of substance. Nor has he demonstrated much decision-making or leadership ability.

This is reflected in the somewhat whimsical way that his presidency is run and in the ideas on which it is based.

"The model we have is unique because it includes Islamic philosophy," said presidential adviser Pir Hosseini in a recent interview in Tehran's old prime minstry building -- now Iran's verison of the White House.

He said the particulars of Bani-Sadr's Islamic philosophy were too complicated to explain at one sitting but that basically the president believed in what he called tamimeh imamat, the idea that everyone should become a Khomeini.

"Bani-Sadr has written a book about it," Pir Hosseini said. "It's based on nonconcentration of power. Meanwhile we provide a situation of freedom with all the things necessary for a person to grow and show all his own abilities. His idea is to build up a society where person growing so much they reach God. Any organization should have this Islamic philosophy. We are trying to realize an Ialamic concept of nonconcentration of power."

Bani-Sadr's aide added confidently, "the new organization of the country will be based on his theories and his philosophy."

The 28-year-old Pir Hosseini said Another element that makes Bani-Sadr's presidency unique is that "it's so decentralized that even though he has a lot of people working for him, they have direct access to him any time during 24 hours. He is heading 20 people directly."

Most of the presidential sides, he said, range in age from 28 to 35. They seem to be mostly Bani-sadr's creatures, loyal to him and his aides. They are responsible -- in a rather unsystematic way, it appears -- for various sectors of activity and act as liaisons between them and Bani-Sadr.

The collective inexperience of Bani-Sadr and his aides, however, means that although Bani-Sadr is president and commander-in-chief of the armed forces, his relationship with various revolutionary entities (such as the Revolutionary Guards and komitehs), other government bodies, provincial and local administrations and political parties are ad hoc and tenuous at best. a

Many top officials now in charge of things in the country were inherited from the provisional government set up immediately after the revolution, and much of the bureaucracy is a hand-me down from the shah's time.

Exemplifying the working of Bani-Sadr's presidency is a day in the life of Pir Hosseini:

Nominally in charge of public relations and industrial affairs on Bani-Sadr's staff, he is a member of the "Stanford Mafia" of young graduates of that California university who have gathered around Bani-Sadr.

He holds a master's degree in mechanical engineering, and says his past experience includes working in a steel mill and doing pollution research for Iran's Environmental Protection yagency. He dropped further studies in the United States and came back to Iran in May 1979 at Bani-Sadr's request.

Like his mentor, Pir Hosseini affects a casual attitude toward the trappings of power and protocol. Sitting behind a desk in a makeshift office, he wears an open-necked shirt and makes notes on stationery that still carries the old imperial hallmark, a lion and sun topped by a crown.

He seems surprised when told that the bodies of eight American service-men, killed in an attempt to rescue the U.S. hostages a few days earlier, are in the hands of the militants occupying the American Embassy and that Ayatollah Sadegh Khalkhali has just finished displaying them at a news conference.

Demonstrating the workings of the system he describes, he picks up the telephone and calls Bani-Sadr to ask if he knows about such an event.

Told that the president is not in his office, Pir Hosseini calls the chief of joint military staffs, Maj. Gen. Hadi Shadmehr, and is told there has been a misunderstanding, that the Air Force thought Khalkhali was going to take the bodies to the morgue when it helped him bring them to Tehran from the crash scene.

For Pir Hosseini, it is another problem that Bani-Sadr does not need. And lately there have been many.

"Things have not been going well these days," he conceded. "Most of the time we have been in critical situations."

He added, "We have not been engaged in rebuilding the country. Because of the different conspiracies in the country we have spent all our time trouble-shooting."

A case in point, he said, was a recent spate of violence on university campuses between leftist students and Moslem fundamentalists, which came to a head at Tehran University when leftist groups initially refused to obey a presidential order to move their offices elsewhere.

The case was a milestone in Bani-Sadr's losing power struggle with clerical hardliners and Islamic militants because, to avoid being outflanked, he was forced to fall in with their drive for a purge of university campuses as part of an "Islamic cultural revolution."

The university clashes also had the makings of major civil strife between the fundamentalists and the disenfranchised leftists. Yet Bani-Sadr's handling of it indicated at seemingly superficial involvement in such domestic problems and a rather nebulous administrative style.

"I was the person who resolved this crisis," Pir Hosseini said. He told of a sleepless night of negotiations among the different parties to end as assault by fundamentalists and Revolutionary Guards and to allow the leftists to clear off the campus before a scheduled speech there in the morning by Bani-Sadr.

"He trusts his advisers very much," Pir Hosseini said. "When he says to solve a problem, he only gives you a couple of directions. Because he trusts you, he gives you a lot of power and freedom."

To prove his point, the curly-haired young aide pulled out a typewritten report about unrest in the northern Gilan Province bordering the Caspian Sea. On it Bani-Sadr has penned three short, squiggly lines.

"You see, he writes a few lines and I know exactly what he means," Pir Hosseini said. "With these few lines I have a week's work -- a commission with several ministers and a trip to the province."

Pir Hosseini insisted, despite what some religious leaders say, that "the highest executive power is in the hands of the president." He acknowledged, however, that the Revolutionary Council has been sharing executive power with the president, and some of its members have been competing with him for it.

"The Revolutionary Council does limit the president's power," he said. "But there's no way to help it. There's a difference between tastes."