Thomas does not believe the heart can know reason. He says as much when you ask him. He is tall with green eyes and no beard except when he came back to school after junior year, and then it was only a week until he left it behind. He lives an ordered life, decorated in plaid and warm lamps and canvas shoes left by the door.

He says that the heart is impenetrable, that it is oceanic in the sense of the word from before the depths of the sea became known. He says that there is no accounting of variables when it comes to the heart, that there is no algorithm to it.

I ask him how this can be. We don’t want to admit that there are reasons that we love each other, I say to him, but there are, aren’t there? We love each other because of proximity and chance and pheromones and hair color and culture and humor and so on.

He stands firm. The heart cannot know reason, he says. It divines in the dark. You can fall for someone you’re not supposed to. You can be left cold by someone you should, statistically speaking, adore. You love or you don’t, and there’s no calculus you can do on a feeling like that.

Thomas is a scientist, or is studying to be one, which sometimes seems strange to me. He should adore knowledge, I feel. He should want to believe that everything in the universe has reasons for where and why and how it is. But I am not a scientist, as is appropriate for someone who got vomitingly nauseous during the AP Calculus exam at the sight of the problems, and I have a certain sentiment that he is onto a deeper science than I can comprehend. From the way he talks, it seems that science’s front guard is often so far ahead that it glimpses possibilities it has no way to test, and, for long stretches of time, it is left to make guesses about the darkness. Certain things, for decades, are unknowable, in the way that Thomas believes the heart is, in the way that Thomas is.

I do not understand Thomas. I am a heretic in saying that I do not know Thomas, but I pride myself on being truthful. We say that we know each other, don’t we? We say it constantly. If he’s down — say, he didn’t get the internship he was looking at — and I find a way to pick him up — say, we ride our bikes to the beach where nobody goes in the winter and smoke pot and build a fire and skip rocks — he will tell me, after, that I know him well, better than anyone. He doesn’t understand that I am performing. He doesn’t understand that I have pieced it together: He will get elegiac about the Oregon coast around that time in late September when nobody will agree to go to the beach with him any longer; he will half-joke that booze is for anxiety and weed’s for depression; he writes poetry that he shows only me, and the image he comes back to, time and again, to represent every emotion and relationship, for good or ill, is the campfire; he told me once, at that time of night when conversation’s strands break apart from each other, that he subscribes to a very unorthodox school of thought on the ideal skipping-rock, and I told him during that darkening twilight on the beach that I wanted to see it in action.

Some people would say that being able to piece this together, to cobble together an experience out of scraps, is knowing someone, but that’s wrong. I cobble because I don’t know him. I latch onto the outer details, the ones that don’t matter, the affectations and airs of the exterior world, because I have no idea what is inside his head. There is something in there — there are thoughts and love and light and truth — but I can’t add his actions together and get his mind. I keep trying, but I can’t do it.

And there are days when this opacity is obvious. When I fail, I know that I will never know Thomas. When I’m happy because I think that’s what he needs, but what he needs is commiseration. When he’s frayed and the signs are that something is wrong, yet I can’t figure out what species of problem he’s having. When I get ahead of myself and make assumptions I have no right to make. I make those so often. I so nearly made one the night I asked him about the heart.

It is a terrible thing, losing love that you never had. Realizing you were wrong, you feel the weight of it all, the jagged ruins of ideas, cutting into your brain and soft tissue. You stay in bed for days. You don’t eat. Yet you don’t have a right to this feeling, this collapse of love, because it’s your fault for having built up the idea that love could be there between you two.

It is a worse thing, falling out of love, or trying to. Love is a dark night, a Santa Ana wind, a fog. Your will has so little to do with being in or out of it. Your will doesn’t make hair in sunlight less beautiful or the crying jags less painful. You want to believe it’s not like this. You want to believe that love can be overcome, cured. You want to know why he didn’t love you back because that’s a first step. And you are about to ask him, you have the words ready, but you can’t even say it because he’s too busy explaining that the mystery of the heart is extraterrestrial, that it’s really less like the ocean here on Earth and more like the depths of the infinitely cold seas on the far-off Saturnian moon of Titan, that the heart, until that impossible day when we have perfect knowledge, simply cannot know reason.

LILY OSLER