It is imperative for Catholics to develop rational arguments to defend the institution of marriage in the public square. We live in a pluralistic society and, therefore, what we accept as revelation is not necessarily accepted by others. However, an argument grounded in right reason—without explicit recourse to revelation—is in principle comprehensible to all persons of good will.
As we consider the current debate over marriage, it would be a mistake to underestimate the pedagogical function of the law and how a fundamental change in marriage law will result in a fundamental change in our understanding of the human person.
What is at stake in the push to redefine marriage to include same-sex partners is not only the radical redefinition of marriage—but, also and necessarily, the radical redefinition of the human person and the entire range of relationships that constitute our basic experience as persons: male and female; husband and wife; mother and father; son and daughter; brother and sister.