The law cannot be divorced from reality, from nature. The moment this happens, law becomes arbitrary, the whim of the ruling power: it becomes tyranny.

Last week, the Maryland Senate passed the Civil Marriage Protection Act by a 25–22 vote. The Maryland House of Delegates had passed the bill on Friday, February 17, by a 71–67 vote, and Governor Martin O’Malley has vowed to sign it. This bill will grant the legal status of marriage to any two non-related consenting adults, irrespective of their sex.

Why is this important, and how does it affect even those who do not live in Maryland? Isn’t it best just to let people do what they want with their lives and leave well enough alone, as long as we are left in peace to do what we want with our lives? That’s a pipedream. This law is a misnomer, and its passage signals the destruction of, not greater protection for, marriage. Let me explain why.

Nature Matters

First, let’s step back from the rhetoric and define our terms. Fundamentally, what defines a marriage? What makes it unique and distinct from all other human relationships? It is the only relationship that naturally leads to the procreation of a child, and, through its stability and mutual commitment, provides the optimal conditions to nurture and educate that child. Same-sex unions cannot achieve this biologically. Two women cannot conceive a child, nor can two men. Therefore, they simply cannot, naturally speaking, be “married,” for their relationship lacks the essential component of fertility. Sexual difference is an essential component of marriage.

Some will claim that homosexual partners raise children just as heterosexual ones do. But again, let’s step aside from the rhetoric and look at facts. Two lesbians who bring a child into the world through artificial insemination still require the male gamete necessary for fertilization to take place. Whether aware of him or not, the child of that lesbian couple actually does have a father. Though same-sex couples may be able to afford the process of artificial insemination or even adoption, their relationship can never naturally produce a child. And this infertility is not due to a defect or flaw in the reproductive system, but is due to nature. This is a primary reason why it is impossible to refer to the union of a same-sex couple as a “marriage,” and to afford it the same rights and privileges. Not only is it impossible, but it is also unjust and arbitrary.

It is because of the unique nature of the marriage relationship that the term “family” cannot be lightly defined. A marriage can only be between a man and a woman; and thus a natural family can only consist of a mother, a father, and the children they conceive. All other families—adoptive families and foster families—are based upon this one. Even the very attempt to give same-sex unions the status of “marriage” and to refer to them as “families” assumes the prior natural institution of the family as its model. Gender is as crucial for marriage as it is for the family that it engenders. Further, children need the complementary love of both a mother and a father. To deny this to children would be far from granting them rights equal to those of children who do have a mother and a father.

A Civil Rights Issue?

Further clouding matters, this has been framed as a civil rights issue. The state, so the argument goes, cannot discriminate against people because of how they choose to have sex; this discrimination is a grave injustice, relegating homosexuals to a second-class citizenship. But if the argument rests solely on personal preference, an appeal cannot be made to a civil right. In other words, the choice of sexual partner does not provide sufficient grounds for the state to formally recognize such a union as a “marriage”; the state’s refusal to recognize a sexual relationship is not tantamount to denying a “civil right.”

A person is more than his sexuality. Sexuality is an essential part of the person, but not the sole defining element of the person. While rightly insisting that their humanity be regarded first and foremost (hence the concern about civil rights), it is actually contradictory for gays and lesbians to follow this up with the accusation that it is discriminatory to deny them the legal status of marriage based on their sexual preference. Their accusation implicitly equates their sexual inclination with their personhood, and takes the denial of legal status to their sexual lifestyle to be a personal judgment against them. It is not a denial of the personhood of gay and lesbian persons to deny their homosexual relationships the legal status of marriage. They are unequivocally persons in fact and under the law, and have all the rights of persons; but their homosexual relationship is denied the legal status of marriage because it lacks the intrinsic element necessary for a marriage: the natural ability to procreate children.

The law cannot be divorced from reality, from nature. The moment this happens, law becomes arbitrary, the whim of the ruling power: it becomes tyranny. The foundations of our very democracy are at stake with this debate, and this affects each and every one of us.

Reason, not Emotion, the Basis of Public Discourse and Law

If Maryland’s Civil Marriage Protection Act becomes law, Pandora’s box will be opened. Once the law redefines marriage as the sexual union of any two consenting adults, further modifications will no longer appear alarming: two consenting adults might become two consenting persons (age therefore being eliminated and opening the door to disguised child abuse), or “two” might be deemed an arbitrary number (already there are lawsuits making their way through the courts), thus opening the door for polygamy and polyamory. When the law can be changed so flippantly, it does not inspire confidence in its ability to “protect.” What sort of “freedom” and “protection” will your children, and their children, enjoy in fifty or sixty years at this rate?

Finally, we need to take a good, hard look at the type of discourse surrounding this issue. Rational discourse seeks truth: it employs premises that flow together to yield a sound conclusion. The pathos-laden language that is being employed in this issue is simply not a valid response to rational discourse. Reason must be answered with reason, not emotion. There is an objective truth that continues to shine in the debate, and it is the simple fact of nature: the essential component that sexual difference brings to marriage. This is a fact of nature that can be clearly seen by reason, and it is here, on the plane of reason, that this Act needs to be assessed by law.

That said, the fact that a good number of persons define themselves by their sexual behavior and interpret as a personal judgment the objective and rational refusal to equate their sexual relationship to that of heterosexuals, points to a very real and objective emotional reality. At some level of their personhood, they are asking to be heard, acknowledged, and accepted, and this is a valid human need.

But this emotional need to be heard, understood, and affirmed is separate from the requisite reasons to justify such a momentous legal redefinition of a primordial institution that precedes the state, and the devastating social ramifications that would result from such a redefinition. As a society, we seem to be losing our ability to distinguish these two planes; we are trying to think with our emotions, and the result is to forfeit thinking altogether. How can we have a dialogue with one another if we lose our ability to reason?

If we want to preserve the democracy that stands on self-evident truths as its foundation; if we want to provide our children and grandchildren with the same protection we currently enjoy; and if we want to salvage the remaining bits of rationality essential to a truly diverse and integrated society, we will stand against bills like the Civil Marriage Protection Act. There is too much at stake in these battles, and there is too much to lose by forfeiting common sense in favor of pathos. The elected officials of Maryland have acted against the will of the citizens. If you are a Maryland resident, you can sign a petition to put the issue of marriage up for a referendum, allowing the citizens of Maryland to decide for ourselves.

This article originally appeared on The Public Discourse. Melanie Baker is a Contributing Writer of HLI America, an educational initiative of Human Life International. She writes for the Truth and Charity Forum.