A phrase often encountered in the “same-sex marriage” debate is “marriage equality.” Proponents use it likening their cause to other movements dealing with equality of one kind or another.
Essentially, the argument goes like this: when heterosexual couples make lifelong commitments to each other it is called marriage and the law recognizes it as such. Therefore, homosexual couples who make similar commitments should be granted the same recognition. Initially, it doesn’t sound entirely illogical. However, upon closer examination we see vast differences.
To begin, the term “equality” means that two or more things are the same or identical in value — not just alike in some respects, but identical. Is “same-sex marriage” really “equal” to heterosexual marriage? There are several ways we can see these relationships are not at all the same, making the phrase “marriage equality” inaccurate.
Perhaps the most obvious way deals with basic human anatomy. Male and female bodies complement each other physically, hence the reason the Church often uses the term “complementarity” when describing human sexuality (see Catechism of the Catholic Church, 2357). Complementarity simply means that the two “complete” each other or are made for each other.
From a simple biological and anatomical perspective, we see that a man and woman truly do “complete” each other. But this also touches upon something deeper, something the catechism refers to an “affective” complementarity. This essentially means that there are two basic ways of being human — as a woman and as a man. The two are not interchangeable.
Our bodies reveal something essential about our identity. Both are equally, fully human, but also unique and distinct — neither has the “complete” human perspective or experience alone. A man only knows what it is to be a man and a woman, a woman. Together, they form a certain human completeness, fulfilling what the other lacks.
Only such a union is able to live God’s design presented in Scripture: “the two shall become one flesh, so they are no longer two, but one flesh.” (Gn 2:24, Mt 9:5, Mk 10:6-9) This makes marriage a completely unique relationship. No such complementarity can ever exist between people of the same sex.
This reveals another major difference. Scripture only approves heterosexual marriage. It is seen as a great blessing and an image of God’s relationship with His people; indeed as an image of the relationship between Jesus and the Church (Eph 5:32). By contrast, Scripture nowhere blesses or sanctions a sexual relationship between people of the same sex. Just the opposite, it always and everywhere sees it as incompatible with God’s design.
Finally, another inequality exists with the begetting of children. The only sexual act which can result in new life is a heterosexual one, making marriage between a man and a woman unique and special. By design, no sexual act between people of the same sex can ever result in new life. Every child born into the world has a mother and father, none has two mothers or two fathers, even if raised by two women or two men.
And even in the case of infertile heterosexual couples, nevertheless, their union is procreative in nature — in other words, it is the very act through which new life is brought into the world by God’s design and by which His command “be fruitful and multiply” is fulfilled (Gn 1:28). Indeed, the natural ability for a man and woman to create new life and thus form a family is the foundation of marriage itself, and why marriage is different from other types of relationships.
These are but three examples demonstrating a lack of “equality” between the two kinds of relationships. True marriage is different biologically, theologically and generationally than any union between people of the same sex. To recognize as equal that which is not, cannot make it be so, and reveals instead an effort to ignore or obscure the truth.