The glowing tributes paid to Hubert Humphrey last week express more than high personal regard. They also reflect an uneasy sense of something missing from the Senate, and perhaps the country at large.

I mean persons of national stature who also serve as keepers of the national conscience. That is to say, leaders who can rally the country in times - not of danger, which is relatively easy - but of confusion.

It is especially important now to see Sen. Humphrey, warts and all. He might not have made a good President. He lacks the killer instinct and the capacity to hurt those who would do him in. Hence his inability to stand up to Lyndon Johnson on Vietnam.

If not a downright poor politician, moreover, his sense of timing is at least erratic. He took on John Kennedy and George McGovern at the wrong moments in 1960 and 1972. He did not know how to take on Jimmy Carter in 1976.

Good nature has occasionally made him a poor judge of people. Certainly no man ever derived less luster than Humphrey from his staff. Finally, he does not even make a pretense of efficient management. "I'm a fellow who likes to set out the big building blocks," he often said of himself. "I let other people come along and apply the mortar."

On the big building blocks, though, he has no peer. In season and out, when it was popular and when it was unpopular, Hubert Humphrey has been right on the great issues of the time. He has been right on civil rights - from his debut on the national scene at the 1948 Democratic convention to the present. He has been right on arms control from the early 1950s, when it was a loser, to the full flush of detente and after. He has been at all times right about using the power of government to rpomote economic welfare and better living conditions.

Only extraordinary personal qualities have enabled Humphrey to stay so long with issues that went into fashion and out. It has happened to me more than once to have written stupid things that rightly provoked his ire. But anger waned with its expression.

Humphrey nurses no grudges and bears no malice. He is the foremost national example of good will at work. His own case provides the rationale for what he calls the politics of joy.

His undoubted belief in the goodness of mankind has vaulted his personal interest above self-interest to the level of the public interest. His causes have sprung from the heart; they have not been ego trips. Whatever his stance, Hubert Humphrey has not been a man whom other people long hated, feared or mistrusted.

Thus a career hitched to great issues has survived their ups and downs, and positively thrived in periods of uncertainty and doubt. In good times or in bad, a senator who stood with Humphrey never had to fear losing a thread from the toga. Win or lose, groups that backed Humphrey maintained a respectable position. Right or wrong, he could be trusted.

The absense of trust, in the Senate particularly but also in political life generally, now makes his example shine more brilliantly. The Senate is currently torturing itself on the energy question. Why? Because producer interests do not trust a President who reneged on a pledge to deregulate natural gas, and consumer interests do not trust the basic instincts of the Majority Leader and the chairman of the Finance Committee.

Nor is the lack of confidence a transient matter of the personalities temporarily holding down positions of power. Television is the principal medium by which political leaders now attain national stature. It smiles upon those who know how to package themselves in ways that play on the half-conscious hopes and fears of the massed audience. It deals woe unto those who specialize, as Humphrey has done, in deliberate articulation on identifiable issues.

So an almost desperate timeliness reinforces the praise of Humphrey on his merits. Neither in the Senate nor in the country shall we see his like soon again - if ever.