I feel a very great love for someone, but I'm not sure what kind of love it is, and I'm worried that it might be the wrong kind of love. It has agapic elements in the sense that I want to do good for the person, but it is also rather erotic. Do you have any clear sense of whether there are any necessary and sufficient conditions by means of which I may decide this issue once and for all? Many thanks.

You shouldn't be committed to the classical distinction between Eros, Agape and Philia . These three forms of love are very often intertwined. You seem to oppose agape, an uninterested feeling of caring for the good of the other, to the erotic attraction. But what if your erotic feelings are good for the other person? Don't you think that your making this person a priviledged object of your own desire is good for her or him? It is very difficult to provide a philosophical definition of what "true love" is: Sure, a concern for the other, a possibility of projecting yourself and the other person in a shared future, the joy that accompanies a glimpse of a greater accomplishment of your ideal of a person, all these are ingredients that should be there when you fall in love. I think that love is not so different from trust: it is an accepted vulnerability, a way of opening yourself to the other that encourages him or her to reciprocate. It's a bet on a better life, or on a better "you" that you happen to...

Is is possible to truly love someone, yet still do things that would knowingly hurt them (i.e., acts of infidelity)?

It depends on how you define "true love". Indeed ambivalence is one of the strongest features of human beings, so, typically, you have an ambiguous relation with your objects of "true love". My 7 years old son told me last night: "Maman, (he's French) do you know who is the person I love most?" I replied "No" and he said "You". Then he asked again: "Maman, do you know who is the person I hate most?" I replied "No" and he said "You". I think he truly loves me, still this is the best he can do with his love.