NOTHING ABOUT the brief, tumultuous history of the House Assassinations Committee has been very reassuring. Its genesis was marked by personal and institutional wrangling: between the House and the committee and among the committee members and staff themselves. The thing didn't look even remotely serious for a long time, Its former chairman, Rep. Henry Gonzalez of Texas, and its former chief counsel, Richard Sprague, both had to be replaced after a protracted bout of foolish and degraded antics had reduced the committee's credibility to zero. Add to that the fact that there exits in this country an assassination subculture ready to promote every gruesome, weird and dingbat theory anyone ever could have thought of plus the fact that much has now been brought to light that at least casts doubt on the official versions of what occurred - and you do not exactly have a recipe for hearings that will inspire public confidence in whatever conclusions they may reach.

We mention all this, however, mainly by way of setting it aside for the moment. For the committee is under new managment; its chairman, Rep. Louis Stokes of Ohio, and its chief counsel, Robert Blakey, appear to have managed to glue the wreckage of the committee enterprise back together with considerable skill and also to be pursuing the committee's two investigations (the Martin Luther King and John F. Kennedy murders) with a degree of discretion and decorum that were flamboyantly lacking before. It will be evident in the scheduled public hearings that open today and which will continue in tha fall whether the committee has really gotten its act together. Our point is that the value of its effort should be judged by what unfolds - not by recollections of its recent squalid past or by certain hi-jinx and diversions that are bound to accompany the proceedings.

We have in mind the current controversy over whether an undercover agent of the committee spied on, secretly taped, and stole letters from the brother of James Earl Ray, the convicted killer of Dr. King. This allegation is under investigation by the committee. It is evidently part of a continuing struggle between the committee and Mark Lane, who is representing James Earl Ray. It is a measure of how far the commitee has come from its days and months in the slough of public contempt that people now seem willing at least to hear out its response to the charges and to wait for the results of a committee investigation of what went on.

Given the nature of the crimes under investigation, the fact that in the Ray case there is not even a Warren Commission Report equivalent (i.e., a body of serious investigation material and testimony, never mind how partial and profoundly flawed), and all the passions and interests and prejudices that are bound to come into play with these hearings, you have to expect that there will be much suspicion, conflict and disorder. This, in our view, however, needs to be watched with a great deal of sophistication and discrimination so as to to be able to tell that which is an attempt to discredit or discombobulate the proceedings from that which may be evidence of committee weakness along the old and familiar lines. What we are saying is that the House Assassinations Committee has, by its conduct to date under new management, earned the right to be heard out and then judged by the public. Considering where it started from, that is no mean achievement.