The word “unthinkable” appears to have two meanings. In the first, something is so unlikely to ever occur that we say it’s unthinkable. In the second, something is too awful to contemplate—because doing so would be emotionally upsetting or the contemplated thing is simply wrong so that to entertain the very thought of it would be immoral.

It seems likely that in the not distant past, the currently prevailing legal and elite notions of marriage—a loose association of individuals seeking government approbation of their interpersonal arrangements, which may or may not be characterized by permanence, fidelity or sexual complementarity—might have seemed unthinkable in the first sense. Not that our progenitors would have been unaware of the possibility of failed marriages. They would likely not have suspected, though, that what had been essential characteristics of marriage would become, to use the parlance of fast food, mere sides.

This understanding of marriage is a consistent trope in the court decisions requiring states to modify their marriage laws. Thus, these courts say that when the U.S. Supreme Court has talked about a right to marry (as in the 1967 case, striking down a Virginia criminal statute prohibiting interracial marriages), what is meant was that the U.S. Constitution protects a panoply of individual choices. Not merely protects in the sense of precluding criminal prosecution for making the choice but, in an inversion of the terms, affirmatively requires the government to signal official approval of intimate relationships.

This most recent novelty joins the now entrenched practice of treating marriage as an agreement subject to unilateral termination for any reason. This practice of no-fault divorce began in 1969 in California and is now the uniform law of all the states.

In related developments, the lived experience of an increasing proportion of children (particularly those who comes from families with fewer economic advantages) will be shaped by their parents’ embrace of “family life a la carte.” Parents may or may not pick marriage, they may or may even not pick living together in the same home as their mutual child, one parent may opt to provide emotional but not financial support, and each parent may choose to introduce unrelated adults into the child’s life to act as parent-like but mostly transitory figures.

Indeed, parents may exercise a choice to create a child with the intention of preventing the child from having a relationship with one parent so as to facilitate the commissioning parent’s desire to raise the child alone or jointly with an unrelated adult through surrogacy or other assisted reproductive techniques. Here, adult choices about parenthood abound: a woman may carry a child to term for a fee, a man or woman may “donate” (again, for a fee) the genetic material to create a child with no intention to act as a parent would for their child, couples or individuals can acquire children and even specify genetic characteristics.

A prominent public intellectual has even suggested that it’s time to give up on marriage and concentrate instead on stigmatizing “unplanned parenting” and making long-term contraception the default for couples, so they must “opt in” to having children. Perhaps parenting contracts will become the new form of marriage.

As Elder Erich W. Kopischke pointed out in a BYU devotional earlier this month: “The concept of family and family life as a true source of happiness has been terribly hollowed out in recent decades” in favor of a “desire for self-centered fulfillment” through a strategy of “’low-investment, high return.’”

So, the unthinkable, in the sense of implausible, is increasingly real. There is some reason for concern that some would like the understandings of marriage and family we are abandoning to become unthinkable, as in not fit to mention. In other words, for what used to be the exception to now swallow what once was the rule. In this instance, for one attribute of marriage and family, choice, to become the only salient characteristic, thus making these institutions unstable, impermanent and increasingly unlikely to fill the formative and transformative role they would ideally fill.

Thus, an emerging challenge is to ensure that marriage—the complementary union of a husband and wife, joined as equal partners in a permanent enterprise characterized by self-sacrifice, fidelity and openness to children whose needs will be prioritized above adult desires (described so beautifully by President Henry B. Eyring at the Vatican recently)—remains “thinkable” because it is openly embraced as an ideal and lived out in practice.

This is a challenge because, as President Thomas S. Monson has taught: “Where once the standards of the Church and the standards of society were mostly compatible, now there is a wide chasm between us, and it is growing ever wider.”

That very challenge, however, also presents an opportunity for members of the Church and other people of faith. Since the world is “set on a course we cannot follow” (in President Boyd K. Packer’s words), the course we pursue in trying to live out our commitments to a richer and fuller understanding of marriage and family life will become increasingly distinctive. That will present difficulties, as Elder Russell M. Nelson warned BYU graduates earlier this year: “during these perilous times, life will not be comfortable for true disciples of the Lord Jesus Christ.”

More importantly, it will allow us to present alternatives to the dominant monoculture of low-investment relationships and the treatment of marriage and parenthood as luxury goods to be chosen (or purchased) for purposes of expressive individualism. Elder Nelson made this bracing observation:

Many of your neighbors, colleagues, and friends will have never heard logical and inspired truths about the importance of marriage as God Himself defined it. You will have many opportunities to strengthen understanding of the Lord’s side of that argument by the eloquence of your examples, both as individuals and as families.

This is a powerful mandate that points a productive way forward. We must be eloquent in sharing the logic and inspiration inherent in the old wisdom of marriage. That will require us to set a more exacting standard for those explanations. We also must be eloquent in our example—living the truths of marriage and family in a way more instantly recognizable as praiseworthy and unique.