With the release of a draft pastoral letter on the U.S. economy, the Catholic bishops have once again thrust themselves into the middle of a hot secular debate. You don't have to agree with the letter to recognize that it is mainstream Catholic thinking. "Christian -- and Jewish -- concerns for the poor," observes Archbishop Rembert Weakland, who headed the bishops' drafting committee, "predate the election by several thousand years."

While the bishops waited until after the election to release their draft, its general timing is not coincidental. As the bishops note, the church is concerned about the recent -- though so far slight -- drift toward still greater income inequality in this wealthy country, as well as the growing inequality in world income distribution to which this country's economic policies may contribute.

A group of Catholic businessmen and other prominent lay persons was so worried by the expected anti-capitalist tone of the bishops' draft that it launched a preemptive strike last week in the form of its own economic statement. On the opposite page Michael Novak, vice-chairman of that group, complains that the bishops' draft reads "more like the platform of a political party than like a moral statement." Its tone, he says, is "whiney" -- an adjective now much used in describing people who worry about the poor.

On a more substantive level, the lay committee argues that the bishops' emphasis on income distribution disregards the major contribution that economic growth, made possible by capitalism, can make in helping the world's poor. That's an important point. But strong economic growth is not necessarily incompatible with a considerably more equal distribution of income. Almost all the high- growth countries of Western Europe as well as Japan have much less income inequality than does the United States.

The bishops do espouse a number of programs that have become a standard part of the liberal agenda: less taxation on lower incomes, education and child-care aid, national welfare standards and job programs. But, as Mr. Novak acknowledges, the draft is in many respects more "pro-capitalist" than earlier church pronouncements. While respecting private property, the church has long worried about concentrations of both economic and political power. It has warned that material goods should serve the needs of all humanity and insisted on such non-market rights as the claim to a "just wage." In this statement, the bishops are careful to stress the need for "balance between individual initiatives and the common good."

The bishops seem to be reminding the political right, which has found common cause with Catholicism in opposition to abortion, that the church's concern for life does not end at birth. This is not a radical or even necessarily a liberal position. Conservatism is not identical with a belief in economic Darwinism. There is a far older strain in conservative thought that is concerned with preservation of the social fabric, in all its parts.