Something came up on the TV that made me wonder about this. I understand that we can account for certain aspects of the feelings of love that humans experience. First, what is the limit of this understanding. Next, how do we account for the many [philosophically] different types of love that we also seem to distinguish with our feelings? For example, I feel a different kind of love for Tsu than I feel for my brother or mother. If we can to any extent, how do we make this distinction - chemically, or physiologically?