The early weeks and months of each new activist American presidency require the young in heart and health, if not necessarily in years. The rush to set the national agenda after a long wait in the wilderness, the list of unmet national needs crying out for attention, the time-consuming demands of moving into a new position with a new team and program-these are the pressures, not workaholism or grandstanding or misplaced priorities, that drive the cruel White House pace and schedule in the first 100 and more days of a new administration. Under those conditions, youth can provide a valuable inoculation against burnout.

In the early spring of 1961, no one burned out. The President was 43. His national-security adviser was 41. His press secretary was 35. So was his attorney general (and brother). I was 32. His cabinet was the youngest in the 20th century.

Yet few, if any, voiced the criticism now heard in some circles about the Clinton team-that we were too young. On the contrary, youthful energy and idealism were in the saddle in Washington then, as now. The youngest man ever elected President of the United States had succeeded the oldest ever to hold that office. Citing Jefferson’s work on the Declaration of Independence and Madison’s work on the Constitution, John F. Kennedy had rejected attacks during the campaign-some subtle, some not-on his maturity and experience. The test, he said, is in the man, not his age, in the breadth of his judgment, not the length of his years or service. He applied those same tests to the rest of us.

Even that hard-bitten veteran of Washington intrigue, the President’s father, Joseph P. Kennedy, defended the young team that his son had enlisted. Urged during the 1960 presidential race by Bronx boss Charlie Buckley, who was disdainful of our callow campaign crew, to “get Jack to add some experienced pols,” the “Ambassador,” as everyone called him-mindful of the 12 years that had elapsed since the last Democratic presidential victory-snorted: “Hell, those ’experienced’ guys are only experienced in losing!”

Only once did JFK fall briefly into the age trap in constructing his administration. Mistakenly believing that Averell Harriman at age 69 was no longer up to any demanding role, the President shunted the former cabinet member and New York governor into a roving ambassador-at-large position in which Harriman could set his own pace. He sure did. Uncomplaining (and newly equipped with a hearing aid), Harriman soon proved the equal of a dozen younger men and rose rapidly in both Kennedy’s esteem and the State Department’s hierarchy, first to assistant secretary of state and then to under secretary. Overnight flights to faraway capitals and endless negotiations did not faze our “youngest” diplomat.

Age is by itself no predictor of success in government. After the 12 years of Ronald Reagan and George Bush, the appearance of so many youthful faces in the Clinton entourage (beginning with the President and First Lady) is a marked, almost startling, contrast, welcomed by most, if worrisome to some. But it is savvy, not looks, that will determine the value of these young men and women to government. Gray matter, not gray hair, is what’s required.

No doubt, long before the Clinton administration has run its course, some of its younger members will have proven to the most dubious skeptic that their judgment is solid and their advice astute-and some will have proven to be failures. The same will be true of Mr. Clinton’s oldest appointees and all those in between. And at least the younger ones, less cynical, less blase, will be more likely to retain the stamina and enthusiasm that their responsibilities require.

Nevertheless, I do hope that Clinton appointees of every age and office will take every opportunity to get more sleep, more exercise and more time with their families. Even among the fittest, the fatigue produced by constant round-the-clock sessions can cloud judgment and strain tempers, as I witnessed firsthand during the Cuban missile crisis and on other occasions. Fortunately, with a little luck, the pace may be less intense in the months and years ahead (except when war threatens, Congress balks, disaster looms, budget deadlines approach or a dozen other kinds of all too common emergencies disrupt a more orderly workweek). Kennedy, for example, after sending 277 separate new requests to Congress during his first 100 days, sent fewer than that during the next 12 months.

Looking back 32 years, I confess to a little shock myself over how young I was to be advising the President of the United States. Certainly I have seen a lot more of the world now than I had ever seen then. But I have also seen, in dozens of countries as well as our own, countless young presidential advisers and cabinet ministers who brought to the service of their respective countries a discerning wisdom and thoughtful insight that no elder statesman could surpass.

Youthful appearance and age, in short, are not disqualifications for high government service. Nor are they enduring. No doubt White House Communications Director George Stephanopoulos is annoyed when he is repeatedly described as “even more youthful in appearance than his age.” But bear with it, George, as you may recall I did when Teddy White applied those very same words to me in 1959. Come to think of it, you may not remember-you weren’t even born yet.