HOW DO you keep government decisions free of the taint of outside money? The answer: imperfectly. The ethics-in-government act that Congress passed in 1989 is an example.

The money never goes away. All that changes is the form in which it is tendered. This time it was in the form of honoraria. The point had been reached where as much as an eighth of Congress' earned income was coming not from the Treasury but from these speaking fees from interest groups with business before the members whose uplifting speeches they were paying to hear.

The House voted rightly to put itself back on the public payroll, trading a pay raise for a ban on honoraria. But in an effort to make the bill airtight and uniform, it was taken too far. If it's wrong for the members to take honoraria, it must be equally wrong for their influential senior aides to do so -- as it turned out some aides were doing. If senior congressional employees were to be barred from accepting such payments, symmetry required that comparable employees in the executive branch be barred from accepting them as well. In the end the House simply banned the payments government-wide, except for the members and employees of the Senate; that blank was left for the Senate to fill in.

The Senate didn't do it. To avoid either voting for a pay raise or reducing its income, it decided to risk the opprobrium of keeping honoraria, and it remains today the exception to the standard it willingly imposed on the rest of government.

The term "honorarium" was also broadly defined in the legislation for fear that if it weren't, the interest groups and members would cheat. The ban, to take effect next month, applies to fees for any speech, article or appearance. The silly result, under regulations just sent out, is that no federal employee can accept a fee for even the most innocent of work on his own time, from a scientific paper to a hobby article. That's more than was wanted, and various employee groups are understandably protesting. Among other awkward aspects: no dollar limit exists on the outside earnings of government employees below GS-16, so that a GS-15, say, could write regularly for a publication if he were simply moonlighting and on its payroll, but couldn't write occasionally if he were paid by the piece.

So the Senate tried at the end of the last Congress to amend the act to permit employees below GS-16 to accept honoraria so long as their speeches, appearances, etc., had nothing to do with their jobs and the paying parties had no interests they could "substantially" affect in their official capacities. But at that point the logic of "if this, why not that?" went into reverse, and the question was asked, why can't the same rule apply above GS-16? The separatists -- those who want to keep government and outside money separate -- saw their clear line starting to blur. For that and lack of time, the bill died in the House; it will come up early next year. If Congress weren't its own tolerant policeman -- and if members weren't intended to represent the groups that support them -- it might be easier to write legislation that did what was wanted. As it is, it's hard.