CONGRESS THIS WEEK is facing two more of those self-imposed crises without which it seems increasingly to be unable to act. On Thursday most of the government will run out of spending authority because only one of the 11 regular appropriations bills for the executive branch has been enacted for the fiscal year that began six weeks ago (the budget for which was submitted to Congress last Feb. 4). The House is proposing to pass a three-week "continuing resolution" to tide the agencies over until early December, by which time the regular appropriations process will presumably be further along.

In the second of the week's two non-events, the Treasury on Friday will run out of borrowing authority because the two houses have been unable to agree on a bill to lift the debt ceiling, the limit on total debt the government can have outstanding at one time. Indebtedness is about to pass $2 trillion, a symbolic figure that many members are loath to vote for, even though it is nothing more than an aggregation of decisions already made, the accumulated budget deficits of the past. As a way of cloaking their votes -- and to some extent also as an expression of frustration -- each house has added to the bill a version of the Gramm-Rudman amendment promising a balanced budget in five years. But the versions differ -- the Democratic House would start the deficit cutting right away and put more of the burden on defense -- and there is a threat of impasse. There is also a possibility that the fight could spread to the continuing resolution, which both parties in the House are gearing up to cut -- even though the cuts would last only three weeks -- as proof of their good intentions.

The instinctive response to all this is to denounce Congress, again, as weak-willed and ineffectual -- and the president and others surely will. But while this description may be true it is not quite fair. There has always been a limit to what a Congress can do. It can alter a president's policies; it cannot easily produce a policy of its own. And President Reagan will not produce a meaningful deficit reduction plan; his power has all been used the other way. Congress has gradually taken back more than a third of the first-term tax cut, put a pause to the defense buildup, signalled that there are limits to the further cuts it will countenance in domestic programs. It cannot take the next step and create an affirmative deficit reduction plan of its own -- and the president will not.

The Gramm-Rudman amendment is in part an effort to force him to. Its many disadvantages are by now well understood. It would be government by meat-ax and an abdication of responsibility. But the House version especially could also compel the president finally to do what for five years now he has refused to do: either finance the defense buildup or cut it back. Clearly the Gramm-Rudman amendment would do some harm. The question is whether the president's deficit does more.