Margaret Fuller, once co-editor of a sort of magazine/newspaper/litmag The Dial with Henry David Thoreau, also has three levels of love she describes in her book, The Great Lawsuit. These are:

  1. Mutual Idolatry

  2. Intellectual Companionship

  3. Spiritual Union

The idea here is that the goal of any and all relationship(s) is to learn and grow as much as possible (whether you consider this to be growth in character or developing talents, I don't really care. I figure it is personal and I will use the term vaguely so that it is open to interpretation). In a relationship at the first level, one person is progressing at the expense of the other. One considers himself or herself to be the mentor, teacher or superior of the other--that he or she has nothing to learn, but rather everything to show and tell--in other words, the relationship is not equal. When one member is willing to stall his or her own progression in favor of the other's benefit, (or, alternately, if one is content to learn at the other's expense)then the relationship is mutual idolatry and based on one aspect of love only (generally physical attraction), and therefore incomplete.

At the second level, intellectual companionship, both persons are learning and growing, but the progress each makes is independent of the other. Neither is holding the other back, but likewise neither is particularly helping the other. These relationships are often found in political marriages and marriages of convenience, and are not bad relationships. They can be quite comfortable, but will just never quite reach the level of fulfillment one or both may desire.

The third level, spiritual union, is that where each is boosting the progression of the other. Each person involved is gaining from the relationship. Not only do they learn and grow more in this relationship than they would alone, but they learn and grow together. This relationship is equal, mutual and lasting.

Although Fuller describes these three levels in reference to marriage, I think they can be applied in any kind of relationship--with friends, family, or significant others. Fuller's idea of progression is, I think, a very healthy way to look at what you want from life and relationships. I agree that "the only object in life is to grow." (Margaret Fuller)

Note: This sounds like a very cold judgement of what relationships are and should be. I sincerely believe that Mutual Idolatry is not based on friendship, but rather lust-- that Intellectual Companionship is based on friendship, but rather lacks the physical attraction or extra something which makes up that extra something--that Spiritual Union is where you have that friendship, you have that lust, and you have what you need to take what you get and go on from there--to learn from what life deals you and play your cards together--no one holding the other back, but each gaining from what the other has.