THE SENATE ETHICS Committee has come to a pivotal point in its inquiry into the financial affairs of Sen. Herman E. Talmadge (D-Ga.) and the allegations of wrongdoing that have been flying back and forth for months between Mr. Talmadge and Daniel Minchew, his former top aide. The committee has charged Mr. Talmadge with five violations of Senate rules, involving alleged improper official-expense claims, conversions of campaign funds to personal use, and failures to report various transactions accurately or at all. Public hearings, the Senate equivalent of a trial, are scheduled to start on Monday.

Now it comes out that efforts have been made to negotiate a settlement. Reportedly both sides have some interest in a deal that would involve aborting the hearings if Mr. Talmadge admits some misconduct and accepts some form of Senate discipline. So far, they have not come to terms.

What should one make of this? There are many possibilities. Speculation at this point is presumptuous and fruitless besides. And that is one more reason why more of the truth about this case needs to come out soon. Enough has been disclosed to make it obvious that some irregularities, at least, occurred. Since the inquiries began, Mr. Talmadge has repaid the Senate $37,125.90 for expense reimbursements improperly claimed, and has filed some amended campaign reports. He has blamed these problems mainly on staff errors. He has also stated that he habitually accepted pocket money, meals, loding and clothes from friends and supporters in Georgia-and is unable to document any of these "gifts."

Then there is the much-publicized "secret" bank account, set up by Mr. Minchew in Mr. Talmadge's name, which became a conduit for perhaps $39,000 in additional improper expense claims and diverted campaign funds. Mr. Minchew bas asserted that he managed the account at the senatorhs direction and mainly for his benefit. Mr. Talmadge has denied that and reportedly accused Mr. Minchew of "embezzling."

If the inquiry runs its formal course, with full hearings and committee recommendations to the Senate on each charge, the public is likely to learn what really happened. If a negotiated settlement is reached, the committee has perhaps a heavier obligation to set forth the facts and the reasons for its conclusions in clear, comprehensive form. As the panel's members know very well, Sen.Talmadge is not the only one whose standards and fidelity to the rules are being judged. People are bound to regard this as a major test of the Senate's willingness to carry out the joyless task of governing itself. The outcome certainly does not have to be harsh or compassionless in order to be seen as just. But it does need to be explained.