''I don't see a lot of loose cannons around in corporate leadership,'' Mr. Brown said. ''What is new is the greater use of various techniques to take over a company against management's will,'' so it is understandable that executives have taken steps to protect themselves.

That isn't the public belief. An annual Louis Harris poll that measures public confidence in corporate executives showed that only 18 percent of those surveyed last year placed ''great confidence'' in American executives - down from 29 percent in 1973 and 55 percent in the mid-1960's. Another poll, by the Opinion Research Corporation, found that only 29 percent of Americans in 1983 rated corporate executives ''excellent or good'' in ethical practices. That was down from 33 percent in 1981 and 36 percent in 1975. Two things that seem to bother people the most, and that have come to symbolize the current sense of excess, are ''golden parachutes'' and ''greenmail'' - both children of the recent takeover phenomenon. The first is a huge payment made to an executive after his departure from a company. As distinct from a pension upon retirement, the increasingly frequent parachutes have often been arranged in the heat of takeover battles to guarantee corporate heads who may later fall out of their jobs a soft and cushy landing. Sometimes golden parachutes appear to be rewards for failure, which is not what the capitalist system is supposed to be about. Another sort of pat-on-the-back for stumbling went to Roger E. Anderson, who was chairman of the Continental Illinois Corporation in Chicago during the years of wild lending that resulted in Continental's failure and the Federal takeover this summer. By then, Mr. Anderson was five months into comfortable retirement, having left the bank under a cloud in February, but with a hefty six-figure annual pension intact, plus cash payments worth $280,000, and his club dues taken care of for a year. The most cited recent case of greenmail - rewarding a raider to leave a company alone by buying his stock at a premium price - occurred this spring and summer, as Walt Disney Productions fought to escape a takeover by Saul Steinberg's Reliance Group Holdings Inc. Disney first diluted its own stock by agreeing to acquire a real estate development company and a greeting card company for $525 million in newly issued shares. When those tactics failed, Disney's management succumbed to Mr. Steinberg and paid the financier $325.5 million for his 11 percent stake in the company. Ordinary shareholders were not included in the deal, and within a week of the buyback their stock had declined by 31 percent, to well below what Mr. Steinberg had been paid. Not surprisingly, management is now faced with several shareholder suits - and also a new takeover threat. This time it's from Irwin Jacobs, like Mr. Steinberg a financier who frequently buys large stakes in corporations. Whether Mr. Jacobs will try for a quick greenmail profit is anyone's guess, although Disney officials insist they won't pay off this time. ''GREENMAIL is wrong,'' said Arjay Miller, who has been president of Ford Motor, head of Cummins Engine and dean of Stanford University's Graduate School of Business, and now is a director of nine corporations. ''It isn't often I think there ought to be a law, but there ought to be a law against this.'' A. Bartlett Giammati, president of Yale University, considers the deterioration in corporate stewardship part of a larger phenomenon - the ''disenchantment with the idea of institutional loyalty.'' ''Institutions, corporate or otherwise, are the means for translating private impulse to the public good,'' Mr. Giammati said. ''If people begin to become disenchanted with the idea of the viability of institutions, then the public good gets lost and the impulse to private gain has nothing to connect itself to except itself.'' That's a view somewhat shared by writer Mark Green. Mr. Green, a former Ralph Nader associate whose next book, with co-author John Berry, will take a look at management waste and bureaucracy, believes that ''the mushrooming instances of greenmail, insider trading investigations, and unwarranted pay and perks all trace to the same origin - a bottom line stressing not profits and performance but rewards for managers . . . a prevailing business ethic seems to be what's in it for me.'' Executives may be particularly tempted to use their power to put their own interests first because of a deep uncertainty about what the future holds in the way of recession, inflation, damaging interest rates or a falling stock price, which can quickly make a company a relatively inexpensive takeover target. ''You'd be amazed at the insecurity at high levels - it's not even a stigma to be fired any more,'' said Carl Menk, a top executive recruiter now with Canny, Bowen in New York. That threat of hostile takeovers appears to be especially troubling. Michael Klein, a prominent securities lawyer with Wilmer, Cutler & Pickering in Washington, told a Congressional subcommittee recently that his experience as the father of an 11- month-old and the brother of a psychiatrist ''tell me that if you threaten to take away something from someone else that is the source of his power, of his prestige, and indeed, of his economic welfare, even the most rational and reasonable person is likely to strike out and behave in a rather untoward manner.''

BUT perversely, the glamour, the excitement, the rewards of business all seem to be in the financial wheelings and dealings of takeovers.''Everyone wants to be Bruce Wasserstein and do deals,'' says a Manhattan stock speculator, referring to the managing director of mergers and acquisitions at the First Boston Corporation, a fast-moving 36-year-old who enjoys a seven-figure income and a multimillion-dollar estate in East Hampton. There are other theories as to why some of the traditional constraints on corporate behavior appear to be unraveling. The first usually mentioned is the avowed intention of the Reagan Administration to dismantle what it considers to be excessive regulation. ''There is no question that the country has been moving to the right starting back in the 1970's,'' said Alan Greenspan, an economic consultant who was chairman of President Ford's Council of Economic Advisers. ''What we are seeing is a loosening up of entrepreneurship. In its most ethical form, the individual is given freedom to act, invest in new products, succeed, and make a hundred million bucks. However, these types are rare in all endeavors - business, politics, education - and the shift has removed the covers from more unsavory types of people.'' James Tobin, Nobel Prize-winning professor of economics at Yale, puts it more strongly. ''The undiluted pursuit of personal gain is more accelerated in society, as a result of the conservative ideological revolution,'' he said. ''It affects the way businessmen and everybody else looks at what they're doing.'' Examples of the stampede of self-interest have become the bread and butter of the daily press:

* A handful of top auto executives receive from their boards of directors bonuses of more than $50 million. That raises eyebrows and angry comments because the executives, citing weak car sales, had won $4 billion in wage concessions from Ford and General Motors workers, had laid off thousands of other employees, and had won protectionism from Japanese imports that cost consumers millions of dollars in higher auto prices. When a reporter asked Betsey Caldwell, the wife of Ford chairman Philip Caldwell, whether he deserved a bonus of $7 million, she said, ''How can I answer that without sounding like Marie Antoinette?''

* Less than four months before the Charter Company filed for bankruptcy in April, its top five officers voted themselves special incentive bonuses of $250,000 each. And one month before the company, an oil and insurance conglomerate with $5.6 billion in annual revenues, slid into the abyss, its accounting firm, Peat Marwick, gave it a clean bill of health, certifying that Charter had a book value of $28 a share. In the annual report, the chairman, Raymond K. Mason, assured shareholders that the company's ''financial condition continues to be strong.'' But a few weeks later Charter's shares, once worth $50, had shrunk to $3.125 a share. Peat Marwick, one of the nation's most prestigious accounting firms, insists that its Charter audit conformed with accepted accounting rules. But that audit did not reveal the lack of cash flow that put Charter under.

* When the American Law Institute, a group of distinguished Establishment lawyers, decided to look into corporate governance, in order to toughen the law relating to the administration of large corporations, some members of the Business Roundtable, including Andrew Sigler, chief executive of Champion International and chairman of the Roundtable's Committee of Corporate Governance, took it as a major threat to capitalism and tried to derail the project. Among other things, lawyers from several companies in the Roundtable called some major law firms and threatened to take their companies' business elsewhere unless the A.L.I. reined in its corporate governance project. The campaign has not succeeded, but the institute is considering scaling back the most controversial portion of the project, relating to mergers and acquisitions.