[Maédhros]

From Morgoth's Ring: The Later Quenta Silmarillion

But Ulmo answered her saying: 'Nay! Though I do not condemn, yet still I will judge. Herein I perceive not only the direct will of Eru, but fault in his creatures. Not guilt, yet a failing from the highest which is the Hope of which the King hath spoken. And I doubt not that the taking of the higher road, an ascent that though hard was not impossible, was part of that purpose of immediate good of which Niënna speaketh. For the fëa of Míriel may have departed by necessity, but it departed in the will of not to return. Therein was her fault, for this will was not under compulsion irresistible; it was a failure in hope by the fëa, acceptance of the weariness and weakness of the body, as a thing beyond healing, and which therefore was not healed. But this resolve entailed not only abandoning her own life, but also the desertion fo her spouse, and the marring of his. The justification which she urged is insufficient; for by the gift of a child however great, nor indeed by the gift of many children, the union of marriage is not ended, nor indeed, having further purpose. For one thing, Fëanáro will be deprived of the mother's part in his nurture. Moreover, if she would return she need bear no more, unless by the renewal of rebirth her weariness were healed.
'Thus Finwë was aggrieved and claimed justice. But when he called her and she did not return, in only a few years he fell into despair. Herein lay his fault, and failing in Hope. But also he founded his claim mainly upon his desire for children, considering his own self and his loss more than the griefs that had befallen his wife: that was a failing in full love.
'The fëar or the Eldar, as Niënna hath said, cannot be broken or forced, and the motion of their will cannot therefore be predicted with certainity. Yet it seemeth to me that there was hope still that after repose in Mandos the fëa of Míriel should return to itself to its nature, which is to desire to inhabit a body. This strange event should issue, rather than in dissolving their union, in the use by Finwë of the patience of full love, and the learning of Hope; and in the return of Míriel, wider in mind, and renewed in the body. Thus together they might forter their great son with joined love, and his right nurture be assured. But the fëa of Míriel hath not been left in peace, and by importuning its will hath been hardened; and in that resolve it must remain without change while Arda lasteth, if the Statue is declared. Thus the impatience of Finwë will close the door of life upon the fëa of his spouse. This is the greater fault. For it is more unnatural that one of the Eldar should remain for ever as fëa without body than that one should remain alive wedded but bereaved. A trial was imposed upon Finwë (not by Míriel only), and he hath asked for justice, and relief.'

In the end, if Finwë had been more patient, Míriel could have returned as she should have and together, they could have raised her son as it should have been.