 Nonetheless, questions can be raised about precisely how to distinguish romantic relationships, grounded in eros, from relationships of friendship, grounded in philia, insofar as each involves significant interactions between the involved parties that stem from a kind of reciprocal love that is responsive to merit. Clearly the two differ insofar as romantic love normally has a kind of sexual involvement that friendship lacks; yet, as Thomas (1989) asks, is that enough to explain the real differences between them? Badhwar (2003, 65–66) seems to think so, claiming that the sexual involvement enters into romantic love in part through a passion and yearning for physical union, whereas friendship involves instead a desire for a more psychological identification. Yet it is not clear exactly how to understand this: precisely what kind of “psychological identification” or intimacy is characteristic of friendship? (For further discussion, see  Section 1.2.)