What is might?

[Ibrîniðilpathânezel]

It strikes me that a distinction is being made here that is not unlike the distinction Tolkien makes between "magic" as it is very commonly presented (that being some external power that is drawn upon through the use of rituals or devices) and the kind of "magic" Tolkien uses that is an internal power resulting from the nature of the being employing it. In his letters, Tolkien's references to "power" almost always describe it in dangerous terms; in L151, he says that possessiveness and rebellion against morality will "lead to the desire for Power, for making the will more quickly effective." Power, in his mind (especially with a capital P), appears to relate closely to domination. Although he does not speak specifically of "might," when one considers many of his uses of it, it would appear (at least to me) that he is speaking of something more personal, of individual strength, as well as individual power. He makes an interesting point about the nature of power in an attempt to explain something about Tom Bombadil:

The story is cast in terms of a good side, and a bad side, of beauty against ruthless ugliness, tyranny against kingship, moderated freedom without consent against compulsion that has long lost any object save mere power, and so on; but both sides in some degree, conservative or destructive, want a measure of control. But if you have, as it were taken 'a vow of poverty', renounced control, and take your delight in things for themselves without reference to yourself, watching, observing, and to some extent knowing, then the question of the rights and wrongs of power and control might become utterly meaningless to you, and the means of power quite valueless.

Now, this is all subjective, since I can find nothing in which Tolkien discusses the difference between "might" and "power" (as he does discuss the difference between magia and goetia), and certainly, the two words are sometimes nearly synonymous. But as I see it, "might" is a quality of the individual, whether it be innate or learned; "power" is something acquired or bestowed, as dominion is acquired (either with kindness or by force) or granted (as Eru gave Manwe dominion as His regent in Arda, which was certainly His to give, as the Creator). One can be powerful but not mighty (for some reason, Eol comes to mind), or mighty but not powerful (one might apply this description to Nienna, or to Maedhros chained to the heights of Thangorodrim).

Okay, the brain is sputtering a bit, here, early morning after a long night. But there's a thought in there somewhere...