China, I think you may be trying to reduce a very large and complex idea to a simple definition that can't possibly cover it adequately. Is there such a thing as love? Of course there is. My wife and I will celebrate our 26th wedding anniversary at the end of this month, and even after all those years she is still my best friend, my closest confidante, the person I trust above all others to understand and care about me, and she can still make me seethe with lust to a degree no other woman I've ever known can do. That's one kind of love.
I have five siblings, two sisters and three brothers, and they are always welcome in my home, I will always be happy to see any of them, and if they ever get into trouble I can help them with, emotionally, financially, materially, whatever, help will be given freely and unconditionally. And I know they'd do the same for me. That's another kind of love.
We have two children, both grown up and moved out now, but while they lived with my wife and me they got every kind of support and assistance and attention we could give them (though not without discipline and rules), which of course is still available at need and they know it, and they've turned into secure and confident adults that we are both very pleased with and proud of. That's yet a third kind of love.
There are four people--two married couples of longevity similar to ours--that we call our dearest friends. We socialize a lot, we talk a lot, we've had similar life experiences and have come to similar understandings of them, and the sibling rule applies to them as well: you need help I can give, you got it. A fourth kind of love.
And there's a fifth. My wife's mother, still going strong at 88, a magnificent old lady who looks like she might outlive us all. And a sixth: my wife's five siblings, three brothers and two sisters. I don't feel about them quite as I do about my own siblings, but my wife of course does, so the sibling rule applies there too. And a seventh: this evening we were at a dinner party hosted by one of those two married couples, their children were there, and one of their sons-in-law, and the man's mother, another magnificent old lady in her 80s. More people whose company I enjoy and I care deeply about. Three days ago I was a pallbearer at the funeral of that particular magnificent old lady's older sister, because her son, one of my dearest friends, asked me to do that for him and his mother. You can't refuse a request for help like that.
So I'm up to seven different kinds of relationships that the word love legitimately applies to, without even having to think hard about it. I'm sure that with a little more effort I could come up with a dozen more, from certain co-workers we depend on to the abstract notion of "our shared humanity." The common threads in them all are trust, care, and concern. Ever seen somebody injured and rushed to help? Isn't that a response rooted in love?
Love means way too many things to be able to pin it down to a simple definition. I love my wife, I love my children, I love my siblings, I love my wife's siblings, I love my friends, I loved my parents (both, alas, gone now), I love my wife's parents, I love my best friends' parents... same word, but it means something different in every case. Complex questions have complex answers.