On Valentine's Day I read two M/M romances. One was cute but lacking. The other was fun and quite believable.
At first, I thought the issue might be the setting. Although neither was especially historically accurate, the first was entirely unclear in its setting. I kept getting confused, thinking it was set in New York City, then being forcibly reminded by a passing comment that it was actually set in London. The second had a clear setting: pirates! I'm not sure any real pirate ever had a heart of gold (I'm afraid I think Robert Louis Stevenson had the right of it when he presented his charismatic Long John Silver as utterly amoral), but I never lost track of where I was supposed to be.
Still, I can ignore a non-historical setting or ahistorical setting or even vague setting if I like the characters. In this case, I was supposed to believe that the main characters had each found their soulmates.
I believed it with the second book, not the first.
Was it the lack of philosophical discussions? My favorite M/M couple, Dom and Silas from KJ Charles' Seditious Affair, are prone to discuss politics, religion, the poet Blake, and anything else that pops into their heads. They love arguing but never in a way that implies that they are trying to beat the other person down; what they love is the challenge of pitting their ideas against an equal partner. Their sexual compatibility is fueled by their conversational compatibility and likewise.
But not all decent couples, M/M and otherwise, have philosophical arguments. I entirely believe that Bingley will make a good mate to Jane without either of them spouting off a word of Kant or Adam Smith. And Tom and Barbara Good of Good Neighbors spend very little time contemplating any of the supposed philosophers that would defend their lifestyle.
The difference lies not in momentary philosophical compatibility but in the ability of the couple to discuss or imagine the future.
It isn't so much that they lay plans whenever they meet; rather, they have an idea about what they would like a marriage/relationship to be like. Even if that isn't what happens.
Although we never hear Bingley and Jane wonder about their future, other people wonder for them. Darcy and Elizabeth converse on how far a couple should live from their parents. Tom and Barbara Good create an entire lifestyle based not such much on a future goal (they live crop to crop) but on a common idea of what makes a "good" life. As do their neighbors, Margo and Jerry. Margo wants to be the wife of a managing director; she and Jerry work for the kudos and amenities of life.
In the two books I read, the less believable couple never seemed to have the slightest idea what a "good" future would look like other than that the one character wanted to own a shoe store and the other wanted to travel (kudos to the author; some writers never get this far). But there was no sense, beyond these vague desires, of what those futures would create. It wasn't so much that the characters hadn't set out their 5-year-plans (most people don't and most 5-year-plans fail). It was that they never seemed to even wonder what life with another person might actually look like other than amorphously nice and amorphously loving.
The second couple had definite ideas about what type of life they each wanted to create and how those visions might overlap: a place to rest, a place to run, a place to clear one's head, a place to finally stop fighting the world. A small homestead. A future of using one's hands rather than being forced to pretend to have a knowledge of books.
It isn't that successful literary couples share a common political cause. Rather, it is that the successful couples share a common idea--some idea--about what constitutes successful "togetherness," an idea which is unique to them. Dom and Silas, for instance, could easily be transported into the modern world, where they would become a kind of low-key power couple; Dom would work for a bureaucratic government office while Silas preached libertarianism out of his bookstore. They would agree about some things and disagree about others. The world of small-highclass-apartment-with-books-shared-by-two-men-obsessed-with-their-jobs would work for them because that's a way of living that both men see as plausible and fulfilling.
It wouldn't work for another couple, which is, of course, the point. Bones and Booth despite their supposedly differing approaches to life and despite Bones' supposed aversion to marriage, share a common (anthropological in one case; experiential and commonsensical in the other) reliance on the family unit as a good place to find one's bliss.
What matters isn't so much a shared philosophy but a shared vision (or, rather, a shared philosophy that creates a shared vision).
Whether this is true for soulmates in real life, I'll leave up to individual contemplation.