Opiniatrety

I guess it isn't implied by what I said. What I was saying is that there's this thing that I prefer to reserve the word 'love' for, and that involves long-term commitment. I want to resist calling simple romantic infatuation love, merely for the sake of distinguishing them. Linguistically, that won't hold up, because people do in fact use the word in both senses. My main point was to distinguish the two concepts and point out that there's a biological distinction that ends up agreeing with that conceptual distinction.

If you're willing to include the "lower" senses of love, then obviously it can be one way. You don't even have to grant that, though. Even if you reserve 'love' for the long-term commitment, I don't think it follows that "X loves Y" is symmetric. After all, Faith may love Randy and be fully committed to him, while Randy is off having affairs with other women. Faith may even come to know that Randy is doing this and still be committed to him. In this case, the relation of love in the "highest" sense of the term is not symmetric.

That seems reasonable--I was mostly going for a wisecrack, and there are in fact other philosophical views of love that force symmetry. I'm inclined to think that a purely emotionalist account of love is wrong--love involves an actual form of relationship with another person. But I'm also inclined to think that love can involve a desire for a long-term commitment, so that rejection doesn't require you to withdraw to your castle a la Kierkegaard's Knight of the Infinite Resignation. Of course, "inclined" here means "I haven't thought it out," and you'd be perfectly within your rights to deny that these cases count as the kind of love you mean.

This is probably silly, but I'm curious about it: Are there cases in which the relation is not symmetric? For instance, suppose A took care of B when B was a toddler. A large amount of interaction occurred, and A has acquired a large amount of information about B's character. But B has no memory of any of this. Years later, someone asks A, "Do you know B?" A replies "I certainly do - I took care of him when he was a toddler, and have watched as he has grown up." Then someone asks B, "Do you know A?" B replies that he doesn't - he has no idea who she is. Even upon being told the role she played in his life, he says "Alright, but I still don't know the person." Is this a case of A knowing B without B knowing A?
I was also wondering if "x knows y" is a reflexive relation: If infants are capable of knowing people, then it might not be - one might say that an infant knows its mother before knowing itself . . .

Not silly at all--that's a good case. I really should say that "X knows Y" is usually symmetric, which is weak. What may be going on here is that knowing a person is a matter of dealing with that person in a certain way in your life, and that in most cases this relationship must be symmetric.