Difficulty in defining friendship

Clearly friendship is a mutual relation between people. Our use of language does not allow us to speak about unrequited friendships. And clearly – this is what everyone mentions when defining friendship – it involves mutual love, or affection. (I use these interchangeably.)

But mutual love, though necessary, is not a sufficient condition for a friendship. For suppose that I learn of some on-line celebrity and fall in love with her, and read all about her as much as I can. Unbeknownst to me, this celebrity has also learned about me, and read about me as much as she can, and fallen in love with me. There is mutual love, but one could hardly say there is a friendship – we have never talked to each other. Some sort of contact seems to also be required.

But what kind of contact? I do not mean here to put a question of media – on-line friends are clearly friends, for instance, as are pen pals – but of frequency. How long after your last contact can you say that a friendship has lapsed?

If two friends spent decades apart, and at least one of them has changed so much that they now have little in common, it would seem that it has lapsed. They do not even know each other, beyond their names and early history; if they do have some knowledge about how they have changed, they have not talked about it. So, if they met and were quickly friendly again, it would seem more fitting to describe the situation as a new friendship starting between the same people than as the old friendship continuing.

But, at least sometimes, it would seem that it can still be the same friendship after many years. It is unclear what the conditions are for this to happen. I would suppose that it involves their knowledge of each other remaining sufficiently up-to-date in some respect. I don’t know, though.