The Reagan Justice Department seldom bestirs itself in the interest of racial integration -- of schools, of the work place or of neighborhoods. But it is absolutely consistent in its opposition to racial quotas.

The department filed suit last week to disallow the use of quotas at Atrium Village, a Northside Chicago housing project specifically created as a model of racial and economic integration.

"While integrated housing is certainly desirable," said William Bradford Reynolds, chief of the Justice Department's Civil Rights Division, "it offends every principle embodied in the civil rights movement to place an artificial, racially inspired ceiling on the number of housing units to be rented to blacks and other minorities for the benefit of whites."

Reynolds is right, of course. How can you justify telling a black applicant that he can't have the apartment he's waited a year or more to rent and then handing it to a white applicant whose name is farther down the waiting list? No matter your good intentions, says Reynolds, to do so "constitutes discrimination, plain and simple."

But the sponsors of the 309-unit development are right, too. They recognize racial (and economic) integration as a positive value, particularly in a city as segregated as Chicago. And they understand all too well that letting the units on a first-come, first-served basis would probably tend to turn Atrium Village, now about 50-50 black and white, into an all-black complex.

The reasons include the fact that blacks have fewer options for decent housing than do whites, for whom the suburbs are wide open. That truth is reflected in the fact that blacks make up some 88 percent of the waiting list for Atrium Village, waiting for as long as three years to claim an apartment there.

In addition, the development is located hard by the 3,000-unit Cabrini Green, Chicago's infamous all-black crime-ridden public housing project. The fear, which seems entirely logical, is that if Atrium Village becomes as black as its waiting list, the number of white applicants will dwindle, eventually to zero.

If whites abandon the development, the likelihood is that middle-class blacks will follow suit, and the project will become not just all-black but all-poor as well, with all the problems that entails.

Managers of the project, built in 1978 by a consortium of Chicago churches using city, state and federal subsidies, say that they have been able to maintain a rough 50-50 occupancy ratio, without resort to quotas for the past year. But they sought an agreement with the Justice Department that would allow them to reinstitute quotas if it became necessary to prevent "tipping."

After all, they say, it was the federal government, under President Carter, that "told us we had to push for whites. They were afraid the neighborhood was too risky, that we couldn't make it work." But the Reagan Justice Department said no deal; quotas are against the law.

What is the right thing to do? Gary Orfield, a University of Chicago political scientist and longtime active integrationist who has taken classes to Atrium Village, is frank to say he doesn't know. "I certainly don't like the idea of treating black and white applicants differently. And yet I know from experience that buildings that go through racial transition tend also to go through economic transition.

"If the Justice Department called me, I'd say, 'Yes, it's discrimination, and that's bad.' If the other side called, I'd say the majority of the tenants will lose something of value if integration fails, and that's bad.' "

Even civil rights activists are divided on the question, some focusing on the desirability of integrated housing, others on the fact that quotas discriminate against housing-short blacks.

"I wish they had put the project somewhere else," Orfield said. "And having put it where they did, they should have tried to come up with some other way of maintaining racial balance. Once the question of quotas is raised, there aren't any good answers."

But there is a good question. "The Reagan administration brings only a handful of housing-discrimination suits each year," Orfield says. "They've hardly attacked any major landlord in the country for discrimination. So the question is, why is the Justice Department doing this?"