THEY ARE HAVING some birthday celebrations over at the Department of Health, Education and Welfare this week. Twenty five years have passed since the department was created. It was created by elevation to Cabinet status a glued-together assortment of bureaucratic bits and pieces, so that what was hailed at the time as a "new" department was really on agglomeration of existing offices: the office of Education, the Social Security Administration and so on. This has been the classic method of creating new departments, and is one energy and high purposes on the part of these newly established entires are usually disappointed. But HEW's history, for better and for worse, has ben distinctive and outside the normal pattern of departmental growth and for that reason, worth mediating on at the end of its first 25 years.

It is almost impossible to recall now the apologetic way in which its backers in the early 1950s felt the need to assure everyone else that the creation of HEW was not a first step in the ineluctable march toward social revolution. It wa - the "reassurances" ban - just a small, humane endeavor; a bureaucratic plying up of overlappint jurisdictions; a modest and manageable commitment to certain generally shared values concerning human welfare. How the times have changed. HEW is vast and its budget gigantic, and, never mind all those 25-year old undertaking to the contrary, viewed against the backdrop of 1963, it has become both a setting and a source of social revolution.

While this fact has produced great anguish on heart of many politicians and is the subject of a certain amount of muttering in the country as a whole, it tends generally to be forgotten that neither the growth of the department not its breaking out of the confines of pre-1963 social doctrine was a result of some internal HEW plot or maneuver.Here are some of the things that had not happened yet when HEW was created. The Supreme Court had not outlawed formal, official racial segregation in the schools of the South; there was no comprehensive civil rights act; there was no Medicare and no Medicaid; there was no comprehensive federal aid-to-education program to preside over and administer. The federal courts and the Congress have vastly enlarged the jurisdiction and responsibilities of HEW in the past quarter of a century, and it is really mindless to pretend, as some people do, that the outsized phenomenon down at Independence Avenue and C sheet, with its proconsuls scattered across the country, is just some self-generated, runaway bureaucratic empire.

HEW, in other words, is not as accident. And we will go further: It is also not a catostrophe. We say that fully mindful of some of the breathtakingly foolish and insensitive acts HEW officials have committed over the years and some of the excruciatingly literal-minded policies it has pursued to the distriment of the values it was purporting to serve. But HEW at 25 is evidence of a preponderantly citizen, especially those with particular needs: the aged,the ill, the schoolchild, the poor, the handicapped, the victim of discrimination. The point about HEW's first 25 years is that they saw a tremendous enlargment of responsibility in a relatively short time, a tremendous expansion of government jurisdiction and concern..And that being so, it is hardly any wonder that the second 25 years begin, with a rising tide of anxiety over both philosophic and nmmanagerial problems that this expansion has inevitably brought with it.

The key word is "inevitably." It is most normal of phenomena that HEW should now be in need of some trimming, rearranging, shaking up and, on occasion, dression down. The main fact is that HEW at 25 stands as testimony to a series of political commitments the nation can be proud of accepting.