THE BUDGET negotiations over the past week have not collapsed. But neither have they succeeded. To achieve agreement, the White House and the various congressional negotiators are slipping toward broad and general terms that seem unlikely to commit anybody to much of anything. That's deeply unfortunate. It means that the prospects of very large deficits, and high interest rates, are going to persist.

The people who initiated this unconventional bargaining process, most of them senior Republicans in the Senate, originally had something quite different in mind. They began with the logic that the projected deficits were intolerable. To reduce them decisively would require a highly specific agreement among the president and both parties' congressional leadership to rewrite the president's February budget. If the agreement was sufficiently explicit, and everybody was committed to it, everybody could cast the hard votes to enact it without fear of partisan attack--even if it required such unpleasant necessities as raising taxes and trimming Social Security benefits.

But it was clear from the beginning that it could work only if Mr. Reagan not only assented, but vigorously and visibly supported it. The past week has demonstrated that Mr. Reagan intends to do no such thing. Unlike the Senate Republicans, he sees no need to change his February budget. In view of his refusal to commit himself, the House Democrats have been understandably reluctant to make promises.

To avoid a collapse of the negotiations, the factions are now working toward another kind of agreement--an agreement in principle, as people say when they want to leave themselves plenty of room for maneuver. It seems likely to produce general figures for increased revenues and decreased spending in several broad categories. But it is not likely to go into much detail. Nor is anyone going to sign it in blood as long as Mr. Reagan maintains his present airy detachment.

That kind of loose agreement may be good enough to enable both houses to pass their preliminary budget resolutions in May. It may also allow the administration to get the legislation raising the debt ceiling, later this spring, without setting off a rebellion among the fiscal conservatives. But this kind of an agreement won't do much to allay the widespread fears of extraordinarily large deficits ahead.

The debate over public spending now appears to be getting sharper and more forceful. Last year, there was a wide consensus that the budget was flabby. But since then it has been wrung out with great severity and now, in a recession year that is also an election year, a lot of people--by no means all of them politicians, or Democrats--are beginning to press the case for public responsibilities and public funds to match them. The electric reaction by the White House this week to a television documentary on the budget cuts and their social effects was an acknowledgment that the atmosphere is changing.

This budget season began with a question: how can the country be rescued from the excesses of last year's tax cuts? The answer seems to be that it can't be rescued unless Mr. Reagan is willing to help-- and, so far, he's not willing.