It is a touchy subject. For years, Harvard has required its professors--some of the world's most prominent scholars--to retire at 70.

Renowned sociologist David Reisman '31 says he, for one, was ready. But others, including former Watergate special prosecutor and Loeb University Professor Archibald Cox '34, would have liked to stay on longer.

Beginning in 1993, when mandatory retirement for professors becomes illegal, scholars will have a choice. And as that year swiftly approaches, the University is preparing to face the complex issues that will follow.

Especially at Harvard, where the teaching load is light and the community is stimulating, officials say this change may move many scholars to consider remaining in their posts long into their later years.

Such an increase in older faculty could lead to substantial policy changes, some administrators predict--policies which some say would throw the security of tenure into question. For instance, Harvard may institute a plan that asks scholars to review their colleagues, to judge whether they are remaining productive.

If there is no mandatory retirement age, then I think, yes, there will have to be [a review] absolutely," says acting Dean of the Faculty Henry Rosovsky. But, he adds, "it is very unpleasant and difficult to review your colleagues of 20 years."

And John Kenneth Galbraith, Warburg professor of economics emeritus, agrees. "It is a difficult decision," he says--a decision all the more complicated at a University where the phrase "lifetime post" is so highly valued.

Yet Galbraith, who chose to step down at 66, says Harvard has a responsibility to make these judgments. "I don't think tenure should protect the no longer competent professor," he says.

Despite Galbraith's "retirement," the economist still runs a busy schedule. At 82, the former presidential advisor and one-time U.S. ambassador to India, is still sought after for his views on world economy and military history.

"If you live this close to the University, you don't retire," says Galbraith. "My experience is you do the same amount of work for half the pay."

Although many emeriti lead active post-Harvard lives, Galbraith says all should have the right to choose their retirement date, as long as their ability to teach and contribute remains consistent.

And that sentiment is just what Congress ruled in 1986, when former U.S. Rep. Claude D. Pepper (D-Fla.) sponsored a bill that forbids age discrimination in employment practices. At that time, universities were given six years exemption from the new law.

When the law was passed, University officials immediately were concerned that professors who stay on long past the traditional retirement age would potentially occupy spaces for new, younger scholars.

At smaller, less research-oriented schools, Rosovsky says, tougher teaching loads will likely lead professors to continue retirement near 65 or 70. But for the nation's top research universities, Rosovsky adds, the problem will remain.

At Harvard, better working conditions may make professors more inclined to remain. For many here, work is their life, the dean says, and most are very unwilling to give it up.

"People like what they do. Most professors don't have hobbies, work is their hobby. It keeps them stimulated and alive," says Rosovsky.

This is not the first time administrators have confronted these questions. In 1988, then-Dean of the Faculty A. Michael Spence commissioned a panel to examine possible policy changes. The Spence committee dissolved without an offical report or decision.

Dean of the Division of Applied Sciences Paul C. Martin '52, a member of the committee, says the group ran into legal questions as they tried to formulate proposals. In addition, Martin says, as the committee progressed, members began to realize that these retirement issues would affect the entire University, not just Spence's faculty.

Indeed, Rosovsky agrees. "It is a big issue, really a University-wide issue," he says.

Pointing to pensions, Rosovsky says financial considerations may be the most difficult to resolve in the retirement issue. Under the University's present system, scholars receive more money the longer they remain in an active teaching role--an arrangement, the dean says, that encourages delayed retirement.

"The longer you stay the more benefits you accumulate. Every year adds a significant amount," Rosovsky says.

According to Harvard's benefits director, Joan Bruce, the pension plans have been under examination. At this time, however, she says there are no changes in the works. And, she says, she is unsure whether professors will allow their pension to influence retirement decisions.

"That is the $64 question," Bruce says. "We don't know what effect it will have. [Retirement] is an individual-by-individual decision."

Vice President for Finance Robert H. Scott says it is difficult to change pensions, not only because of federal regulations, but also because of issues of justice.

"You can't have a policy that gives less to someone who's older, that would be age discrimination," says Scott. "The ideal, which of course can't be acheived, is to have people earn the same amount if they continue to work or took their pension--they would be indifferent."

On an emotional level, University administrators say they hope to make the professors' transitions from active duty to emeritus smoother. At recent Faculty Council meetings, scholars have discussed potential ways emeriti might be further included in regular Harvard life.

Although retired professors can teach first-year seminars, house-based classes or extension school courses, most emeriti say limited office space, not limited teaching, is the more contentious issue.

"It has been a real problem to drive emeritus professors out of office at age 75. Some of my colleagues rather resent it," says Jerome Hamilton Buckley, Gurney professor of English literature emeritus. "I think something should be arranged."

For some however, office space is a little less important. William Alfred '49, Lowell professor of the Humanities, says that he has always used his home as his office and will continue to do so when he retires next year. For Alfred, Widner Library is most important.

"People who do retire, they can still use the library. That is the big thing that mattered to a scholar," he says.

In the long run, administrators say they must balance younger scholars' needs with that of professors who might feel cut off from their community.

"It is obvious that people will be more inclined to retire if it doesn't cut off their professional life," says Martin.

Yet despite this concern, many emeriti say they would not have gone on teaching, even if the mandatory age was not in place.

"I don't care to teach classes, I have had my chance," says Buckley. The English scholar says he remains active with Leverett House and helps advise some theses, but he is glad to take on a reduced role.

"I hadn't thought about going on forever," Buckley recalls. "Retirement at the age of 70 is all I wanted."

Even if they no longer want to teach, some emeritus professors say they still enjoy their relationship with graduates and undergraduates on campus.

"I can't go on teaching my Gen. Ed. course, but that doesn't mean I am prevented from working with students," says sociologist Reisman, who retired in 1976. Today, Reisman continues to advise theses, write, occasionally teach a North House seminar and serve on the Hoopes Prize committee. "I do what Harvard asks of me," he says.

But while Reisman considers himself very fortunate, he says some of his colleagues do feel left out. "I am very much engaged, but I look at some my age, and they have not got that opportunity," Reisman says.