A quote from Michael Novak's piece on the subject at First Things:
More and more often on Catholic campuses, left-wing Catholics are hiding their own ideological preferences behind the mantra “Catholic social thought.” To listen to them, you would think that the Catholic social ethic has four main emphatic tenets and five great silences. The four emphases are: (1) pacifism and nonviolence; (2) legal limits on the income of the rich; (3) the extension of the social welfare state for the poorest 12 percent of the American population (about forty million people), until all are lifted by government grants above the poverty line; and (4) the elimination of the death penalty in the thirty-some states that still allow it.
Merely on the terrain of social ethics, this creed is notable for (a) its silence about ending abortion (forty-eight million since 1973); (b) its silence about federal funding for embryonic stem cell research and cloning; (c) its silence about the fourfold increase in violent crime since 1965—committed disproportionately against the poor; (d) its silence about the sixfold increase in father-abandoned families (chiefly among the poor); and (e) its silence about the horrific oppression of Muslim peoples around the world, including the daily assaults on their dignity by secret police, and the normal, regular abuse of their individual rights. We might call these the five silences. But there are others, too.
Read the whole thing.