Voters -- and the panel in the forthcoming debate -- have a master question to put. It is a question that transcends foreign policy, the economy, energy and all the other cosmic issues. It is the question of competence -- how would each candidate govern?

Badly is the answer on the tip of most tongues, and for the same reason in each case. Jimmy Carter and Ronald Reagan have not been deeply involved in national and international affairs for most of their political lives. On the contrary, each man is a bit of a loner, primarily involved with himself.

Carter came to public affairs by the route of moral ambition. He has sought to give the country a government as "good" as the American people. He has genuinely wanted to make the world a better place.

But in Carter's case, personal zeal for improvement has yielded the worsening of an impersonal problem. Emphasis on human rights back in early 1977 caused the Carter administration to blow an arms control accord with Russia that was all but locked up. The same itch to do right led to the loss of control over events in the Persian Gulf.

Taking the most humane position on unemployment in the early days of the administration yielded, as the president has acknowledged, a weaker position in the more important fight against inflation today. After the effort to frame an energy policy that was the "moral equivalent of war," there followed a letdown that permitted Congress to forge a policy almost empty of moral content.

Reagan came to public life as the ordinary citizen applying common-sense solutions to problems that confounded professional politicians. His instinct is to put into practice his store of folk wisdom, the ideas he has accumulated over the years. But what are those ideas? Well, they were expressed in the unguarded comments the governor made in abundance at the outset of the campaign and sporadically ever since.

He would like to thicken ties with Taiwan. He supposes environmental pollution is "under control." He thinks private industry, if turned loose, can solve the energy problem. He wants to scrap the arms agreement with the Russians known as SALT II. He imagines the threat of a big American defense buildup would scare the Russians into accepting better terms.

In other words, give either Carter or Reagan his druthers on most issues and you have a prescription for chaos. Hope for the next four years depends, accordingly on submerging personality in the institution of the presidency. As rarely before, relations between the president and his staff, and his Cabinet, matter. Most important of all, the country needs from each candidate a statement -- not of personal values -- but of government priorities. Carter ought to raise himself above mere business with infinite detail. He owes himself and the country a large outline of the big things he expects to accomplish over the next few years.

Reagan, by contrast, deals entirely in large generalities. We need from him a detailed agenda of what he regards as critical goals, and how he expects to get from where we are to where he wants to be. Delegation of authority inside the White House is also crucial to competence. Carter cannot be effective if he continues to be his own chief of staff, reading 300 or more pieces of paper a day, and refereeing every fight between competing departments and different groups on his own staff. But is he willing to appoint a strong chief of staff, who can keep the rest of the executive branch doing what the president thinks it should be doing?

Reagan speaks of himself as chairman of the board, doing a nine-to-five job. Maybe that would work. But is he willing to appoint an experienced Washington hand, versed in both domestic affairs and foreign policy, someone like former Treasury secretary George Schultz, as his chief of staff, and in effect, deputy president?

The Cabinet as well as the White House has to be involved in delegation. Every president since Lyndon Johnson has recognized the importance of "lead" Cabinet officers in various fields -- Treasury in economic affairs, for example, and the State Department in international business. But is Carter prepared to name heavyweights to the Cabinet, and give them growing power? Reagan?

For my own part I don't know the answers to these questions. I don't think anybody does. But the more the candidates are prodded on the running of the government, the more they are pressed to assert their priorities, to name the names of their colleagues, the better. For that way the presidency becomes depersonalized. Damage control mechanisms get set up, and institutions are brought into play as safeguards against the personal preferences of two candidates who as individuals show almost no capacity to manage this country's business.