[XPhial]

In response to Esty's idea about the valar and their marriages: Tolkien uses a very common aspect of mythology when setting up these relationships, that of interconnected, but different, natural elements being connected by the personification of a marriage. The example of Aule and Yavanna is a perfect one. Earth and flora are inextricably linked. The earth provides a place for the flora to flourish and the roots of the flora protect the earth. At the same time, the movement of earth destroys flora and flora sap the nutrients from the earth. The relationship between Yavanna and Aule is an almost perfect corollary.

In response to the comments about unequal marriages: Tolkien seems, to me, to be stating that men, through their accomplishments, can earn the worthiness to wed above their station. The only real exception to this is Melian and Thingol.