What's fair in achieving job/wage equity?

First it was ''equal opportunity'' . . . then ''affirmative action'' . . . now ''comparable worth.'' This new concept aimed at ending wage discrimination based on gender is taking root among unionists.

The goal is a laudable and a just one: to set in place employment policies devoid of sexual, racial, or other kinds of bias. But all three concepts are also based on a controversial idea that past abuses should be corrected by policies which employ countervailing bias.

And there's the rub. This argument is sparking conflict between the Reagan administration on the one hand and liberals, minority groups, women's advocates, and other special interests on the other. The groups want the government to sanction job ''preference'' as a sort of restitution for yesterday's (and some of today's) inequities. The government calls for ''equality,'' not preference. The current motto of the US Department of Justice: Don't discriminate to cure discrimination.

Why not? Why shouldn't black firefighters in Memphis be better protected against layoffs than their more senior white colleagues? Why can't Detroit adopt a plan that requires equity in the numbers of black police officers and the numbers of whites promoted? And isn't it just plain fair to give women workers in Washington State thousands of dollars in back pay (as a federal judge has ordered) to make up for years when their salaries lagged far behind those of men in comparable jobs?

All of these are questions for the courts. And all are in various stages of litigation (although the United States Supreme Court last week refused to review a lower court order allowing racial quotas in the Detroit case). They also are becoming issues in political campaigns.

One hopes that, in the end, the legal verdict will support efforts to end discrimination and generally to encourage the hiring and promotion of minorities - without inflicting harsh penalties on other workers. Past decisions suggest the courts may even continue to allow preferential treatment for employees who have long endured disadvantage due to prejudice. But it is likely the courts will resist overreaction, such as huge awards of retroactive pay, a measure which could throw pay plans into chaos and even bankrupt some companies.

Of course, one must take into account performance differences among workers. Gender may play a part in this, as well as cultural background and experience. For instance, a woman without exceptional physical strength would not be discriminated against if she were not accepted for a job on a loading platform. And a high school dropout, whether white or black, would not likely be qualified to do interdisciplinary research at a university.

A sensible, balanced approach by governnment and the courts on affirmative action and comparable worth is needed. But it won't solve the problem entirely.

Bias against hiring or promoting women and minorities is a result of biased thinking. Local, state, and federal fair employment laws have done a great deal of good, but statutes don't necessarily change attitudes. Education - perhaps re-education - about individual dignity and worth does.

Ultimately race, gender, and ethnicity don't determine worth. In the end, Memphis isn't looking just for black or white firemen - but for professionals who can cope with menacing flames. Detroit's citizens are entitled to effective law enforcement. The question of whether their policemen have white or black skins is of secondary importance. And workers in Washington State - indeed everywhere - should be paid their worth, be they male or female.

Of course, this type of reasoning must not become a smokescreen for reinforcing the status quo - in many cases white superiority and male preference. Equality is a goal. And those who have been denied it because of lack of education or job training and past discrimination must be given every chance to move ahead so that they get equal opportunity at the starting line. In some cases, affirmative action or a helpful leg up may be the feasible answer. But such measures should be temporary. And policies based on racial quotas - especially those which are disruptive to long-established seniority policies - should be carefully framed to minimize negative consequences before they are adopted.

It must be recognized that, in the end, corrective litigation and legislation alone won't surmount prejudiced thought. Fears that there is much to be lost if blacks and women take their rightful places in the power structure and the work force must be dispelled. Perhaps what is most needed is a clearer understanding of our basic roles in society.

Discrimination and bias - based on fear, hate, -anxiety, or anything else - is morally wrong. Equality, based on a more substantial perception of individual worth, is right - and just.