The inauguration marks the beginning of a voyage into the unknown. About the next four years one can only hope.

But the inauguration also closes a parenthesis. The transition that now ends offers a good measure of the Reagan administration as it gets under way.

Quick organization of strong, central management from the White House was perhaps the outstanding feature. Edwin Meese, who will supervise policy matters; James Baker, who will manage the various services; Michael Deaver, who will look after the president's schedule; and Lynn Nofziger, the political counselor, make up a strong front four.

Perhaps cracks will open between them. But throughout the transition period, the new administration has had a brain, and been able to cope in a coherent fashion with the flow of events.

Ronald Reagan's day-to-day activities attracted the most attention during the transition. If bad trouble develops, the country may recall the amount of time spent on haircuts and the care and money lavished on dress and decorations. But on the whole, the new president turned the interim period to good advantage.

He developed a favorable in-house consensus in the permanent government known collectively as Washington. He retained the national reputation as a good guy established in the debate with Jimmy Carter. More than ever he has shown us the opposite of Cassius -- a sleek-headed man and "such as sleeps o'nights."

A third important action of the transition was the making of the Cabinet. Basically, that comes down to organizing a series of policy clusters -- or floating crap games with regular players.

The national security game is the best-known game in town. The players -- Reagan's choices for the State and Defense departments and the Central Intelligence Agency -- are all experienced men of proven ability. Those worried about excessive use of force may find a shade to much saber-rattling. Others may not the absence of a broad-gauged, strategic thinker.

My own sense is that the balance is good. Secretary of State Alexander Haig can probably set in motion an effort to reestablish American prestige in the world. Secretary of Defense Caspar Weinberger can move to anchor that effort squarely in the country's domestic realities. Given a president who is not reaching out for business, Haig and Weinberger together can probably hold at bay the National Security Council.

The economic game seems much more problematic. Donald Regan came into the picture as secretary of the Treasury only late in the selection process. He is surrounded in his own department by other players with strong, sometimes eccentric views of their own. David Stockman, the budget director, apart from having strong views, has the special force of know-how that goes with being a former congressman.

So the management of economic policy has not jelled. Discord could mar the performance. Alternately, the Reagan administration could go over the cliff of tight money, like the Gadarene swine.

Disposal of excess baggage was a fourth not insignificant achievement. The nomination and election of Reagan depended importantly upon a large number of dedicated right-wing ideologues. As spoils, these were given membership in a cumbrous array of transition teams.

Thereafter, as daily shrieks from their tribunes in the press announced, the right-wingers were systematically shot off into side pockets. While perhaps not dead, they have been silenced for the moment.

One critical matter of business arose during the transition period. In bargaining for the hostages, President Carter offered a down payment on some of the Iranian claims. Tehran was clearly tempted to pocket the down payment, and then try to pry more out of the new administration. That bit of projected hanky-panky was cut short by Reagan's statement that, while supporting the negotiations, he would not sign "a blank check." So the new administration played a part of the event that lets Jimmy Carter bow out on a note of grace.

If generally favorable, however, the overall performance still leaves room for doubt. It is hard to see how commitments on tax cust and defense increases can be met without touching off a new bout of inflation. Not all the charm of Beverly Hills can long gloss over rising prices. Nor the most efficient management in the world. So things could turn sour and, if they do, there will come back with a vengeance the hour of the right wing -- the period implicit in the new administration.

But having a clear and present challenge provides one blessing. The parlous state of the economy should spare the Reagan administration the dizzying experience that did so much to harm the Carter administration -- the pathetic delusion that during the first year everything was just dandy.