Today the conversations would be harder. In part, this is due to the fact that we now speak different languages. One friend, who was an atheist when we sat around the bonfire and is now an orthodox Catholic, has remained, before, after, and throughout his transformation, a person whose insights about how to live I've valued and benefited from profoundly, despite our constant disagreements. For years, as we were living in different cities, I was surrounded by NYU graduate students. He was surrounded by orthodox Catholics. We'd both done a lot of thinking about sexual morality in our respective lives, but one New Year's Eve, when we found ourselves in the same city for a night, our conversations on the subject were more difficult than they'd ever been before. As our experiences and communities had diverged, so too had our foundational assumptions about what the world is like; and as we explored increasingly complicated paths leading in different directions, we ceased to easily understand one another's field notes.

Eventually, he gave me 14 hours of lectures on Pope John Paul II's Theology of the Body. Listening to hours of it made me understand him much better, even as parts of that worldview remain impenetrable to me. As we think and live, the investment required to understand one another increases. So do the stakes of disagreeing. 18-year-olds on the cusp of leaving home for the first time may disagree profoundly about how best to live and flourish, but the disagreements are abstract. It is easy, at 18, to express profound disagreement with, say, a friend's notions of child-rearing. To do so when he's 28, married, and raising a son or daughter is delicate, and perhaps best avoided, presuming that his notions, however absurd, aren't abusive.

I have been speaking of friends. The gulfs that separate strangers can be wider and more difficult to navigate because there is no history of love and mutual goodwill as a foundation for trust. Less investment has been made, so there is less incentive to persevere through the hard parts. Yet all my life, I've learned the most from disagreeing with people I respect (and even people I don't). More than most, I've kept in touch with old friends as our lives and values diverged, and I've grown very close to new people whose perspectives are radically different than mine.

It floors me: These individuals are all repositories of wisdom. They've gleaned it from experiences I'll never have, assumptions I don't share, and brains wired different than mine. I want to learn what they know. This all struck me as my wife and I made the seating chart for our wedding. Our guest list included people who do Christian missionary work; radical feminist activism; futures-trading for an international energy company; home-making; and that's just four people. Surveying everyone who agreed to attend, I wished I could throw two dozen dinner parties, because there were so many conversations I wanted to facilitate, knowing the quirks of people living in very different worlds that would make them fast friends. I knew if they could bridge the language gap, something the wine, camaraderie, and shared purpose of a wedding helps along, they would marvel at insights from one another they'd not otherwise encounter.