Can I hate someone I love?

I do not think it is possible to both love and hate someone at the same time . Love requires a kind of psychological 'embrace' and 'protectivenes' while hate requires a kind of psychological 'rejection' or 'attack'. I would reject the possibility of loving one aspect of a person while hating another aspect of that person, since I think we must love whole people and not just select parts of people (otherwise, it is not love but selective liking). It is certainly possible, though, sometimes to hate a person that one usually loves -- to have a strong and stable disposition to love someone while occasionally slipping into hate instead. Indeed, since hate is usually a defensive response to a felt threat, and since the loss of love is usually experienced as a very great threat, it is no surprise that we can find ourselves hating (however fleetingly) the very people we have loved.

A couple of months ago, I had an experience which spawned an ethical dilemma which I find fascinating. I had been in a healthy relationship with a girl for some time, but after meeting and getting to know someone else—a girl in my class whom I got to know in a perfectly platonic fashion, so I can't see any wrongs committed on my part at that stage—, I fell in love with this other girl, whilst my feelings for my girlfriend withered and died. Understandably, our relationship could not go on after that, and so we broke up. I think we are both better off now than we were. However, assuming that I had an actual choice between (a) 'giving in' to my infatuation and breaking up with my old girlfriend so as to be happy with the other girl (it seems that we're also assuming no independent will on the part of the 'other' girl!) or (b) resisting my developing feelings for this other person to preserve the relationship I was already in, also assuming that I would, in fact, be as happy as I initially was with my old...

You assume (1) that you can, to a large extent anyway, choose whether or not to let yourself fall in love with someone new versus sustain the love you already feel for the person you are involved with, and (2) that you have no reason to think the new relationship will be any happier than the old (although you also claim to think that both you and your past girlfriend are better off now than you were before). You also seem to assume (3) that future happiness of your new acquaintance would be the same whether or not you allowed yourself to fall in love with her (presumably because without you she would be involved in some other, equally happy relationship). It is usually very hard to know the accuracy of each of these assumptions, but I do not find them unreasonable. On a straightforward comparison of current happiness with probable future happiness of everyone involved, there seems to be no reason to choose one relationship over the other. You seem to suggest, however, that the transition...