TEMPERAMENT ALSO had more to do with the forced departure of Treasury Secretary W. Michael Blumenthal than did policy, which is not likely to change greatly. But it needs to be said that Mr. Carter has chose to resolve this particular collision of temperaments by dropping an adviser of great shrewdness and experience - an international high standing. In fact, if a president wanted to protect the stability of the American dollar, firing a treasury secretary like Mr. Blumenthal would be a strange way to begin. It is as likely to have the opposite effect.

The differences between Mr. Blumenthal and the White House have not been ideological, but rather a matter of very different levels of perception. It has repeatedly been Mr. Blumenthal who has argued the harsh limits of reality to the president's staff, whose long suit is not international finance. Mr. Blumenthal has found himself explaining the obscure but crucial relationships among activities that have forbidden many a bright political move. He is not notably patient or tolerant of what he regards as simplicities. It has irritated him to have to keep at the labor of instruction, just as the instruction has irritated the people with whome he has dealt at the White House.

Mr. Blumenthal's successor, G. William Miller, at present chairman of the Federal Reserve Board, has made it clear that he is following a very similar direction on the basic issues. But the quality of economic policy is another matter. The central group that directs it, at the top of the administration, is suffering severe erosion. In addition to Mr. Miller and, until yesterday, Mr. Blumenthal, it includes James McIntyre, the budget director, and Charles Schultze, the chairman of the Council of Economic Advisers. Mr. McIntyre was not brought in by the president to be an innovator of economic policy. Mr. Schultze is ill and off in the hospital. There is Alfred Kahn, appointed to oversee the campaign against inflation, but reportedly out of favor at the White House on grouds that he is too outspoken for comfort - and too funny and too accurate. Mr. Carter's application of the new rule of loyalty, in other words, works to his o tage: It leaves him with a range of economic advice and depth of competence that is less that what he already had.

So much for today's firings. Tune in tomorrow.