Friday’s Supreme Court decision was a huge victory for marriage. But the court didn’t need to invalidate the lives of unmarried Americans  in the process.

You’ve probably read the last paragraph of Justice Anthony Kennedy’s opinion holding that same-sex couples have the constitutional right to marry. It’s a beautiful description of the love and companionship that can be found in a happy, thriving marriage. It also contains a sentence that insults unmarried Americans (about 44 percent of U.S. adults) of all sexual orientations.

“Their hope is not to be condemned to live in loneliness, excluded from one of civilization’s oldest institutions.” This plus another line, about midway through Kennedy’s opinion, casts the unmarried as lonely: “Marriage responds to the universal fear that a lonely person might call out only to find no one there.”

Yes, loneliness is a universal fear, but marriage isn’t the only cure — nor is it always a cure. If it were, the divorce rate would be a lot closer to zero.

The word “lonely” isn’t what’s so hurtful in here. Everyone — married or single, gay or straight, celibate or the opposite — has pangs of loneliness. The offensive part is that it casts marriage as a full life and singles’ lives as doomed to sadness.

Loneliness is not a permanent condition that all unmarried people suffer. Anyone who has a close friend, or even one reliable family member, has a person to call out to when and if they’re lonely. As I’ve said before and feel the need to say again: The single and childless have families; some of us were even born into them.

Loneliness isn’t a chronic condition either, something you’re “condemned to,” as if serving a prison sentence.

Every time I encounter single-shaming — which feels like a weekly ritual after the reaction to Lindsey Graham’s presidential bid, this Supreme Court decision and the simple fact that it’s wedding season — I reach for Sara Eckel’s book “It’s Not You: 27 Wrong Reasons You’re Single.” In a chapter about how she learned to manage her own loneliness while single in her late 30s, she writes: “People talk openly about their alcoholism, depression, eating disorders, and sex addictions. But who besides widows of long and happy marriages admits to being lonely? It’s the ultimate shame.”

“By adding those feelings of shame,” Eckel writes, “I doubled, tripled, or even quadrupled my pain.” But once she realized that an individual bout of loneliness would eventually subside, “I treated my discomfort the way an athlete does, feeling the burn.”

In fact, coping with loneliness could be a marker of adulthood in the way that being financially independent, living alone or finding a partner is commonly viewed. When Kate Bolick, a serial monogamist in her 20s and author of “Spinster: Making a Life of One’s Way,” writes about her need to figure out life as a single person, she wrestles with this conflation of singlehood with loneliness: “Wasn’t learning how to cope with loneliness integral to learning how to take care of myself? And become an adult?”

I wish that she’d written those sentences as declarative rather than rhetorical, but the meaning is clear: Loneliness is a natural part of life, not a life sentence.