SO DAVID STOCKMAN is going to stay in his

job at the White House. Mr. Reagan has made the right decision, but to have made it indicates a certain largeness of spirit on his part in a moment when he must have been sorely exasperated. The article in The Atlantic Monthly--written by our colleague here at The Post, William Greider, and quoting Mr. Stockman at length--creates new embarrassments for an economic program that was already in serious trouble. But Mr. Reagan no doubt also remembered that Mr. Stockman's contributions to the successes of that program have been crucial. While the quotations will furnish opportunities to his opponents for months to come, the article in many respects merely provides confirmation of much that was widely supposed and some things that were already known about the program.

As you will see if you read the article itself, it is a portrait of a very bright man struggling with the federal budget--that enormous fiscal engine running under inadequate control. The story is told chronologically. It is the record, taken from a long series of conversations beginning late last year, of the adoption of an economic theory and then, under the fierce pressure of events, the gradual abandonment of some of its original ideology and its replacement with a more traditional, pragmatic view of the world. The sense of the world's complexity increases, as well as respect for the random impacts of unrelated events--fragments of good luck and bad--on what first seemed like a clear, self-evident course of action. The tone is not the kind of campaigning to undercut policies or poison rivals that is common in off-the-record conversations. It is the evolution of answers, over many months, to very hard questions.

Mr. Stockman evidently saw, well before the administration publicly acknowledged it, the looming threat of unmanageable deficits. But many others were well aware of those same numbers, since they were openly published by the authoritative Congressional Budget Office. Did Mr. Stockman say privately that the numbers were chaotic and uncertain, at a time when he was using them before Congress with great assurance? Everyone knows that they were chaotic and uncertain. By acknowledging that he knew it, he has marginally increased the administration's vulnerability--marginally, but not much.

The voice heard in this article is one that many readers will recognize--that of a man arguing with himself, worrying at an intractable job, and in the process saying more in private than he would care to say in public. But it's not a voice using the shield of privacy for mere self-promotion. The conversations form an instructive commentary on the processes of government. But it's also necessary to say that memory does not recall anything quite like this sequence--the regular series of 18 highly candid talks, with the tape recorder on the table, followed--and ended--by the misunderstanding over publication. The explanation by both men, that it was a genuine misunderstanding, is sufficiently odd that it commands respect. The result is a highly illuminating-- although, to Mr. Stockman, premature--contribution to the internal history of the Reagan administration.