NOT THE ONLY ONE:

Excerpt from a letter by J.R.R. Tolkien to his son Christopher, 10 April 1944 (The Letters of J.R.R. Tolkien, edited by Humphrey Carpenter)

I sometimes feel appalled at the thought of the sum total of human misery all over the world at the present moment: The millions parted, fretting, wasting in unprofitable days - quite apart from torture, pain, death, bereavement, injustice. If anguish were visible, almost the whole of this benighted planet would be enveloped in a dense dark vapour, shrouded from the amazed vision of the heavens! And the products of it all will be mainly evil - historically considered. But the historic version is, of course, not the only one. All things and all deeds have a value in themselves, apart from their "causes" and "effects." No man can estimate what is really happening sub specie aeternitatis*. All we do know, and that to a large extent by direct experience, is that evil labors with vast power and perpetual success - in vain: preparing always the soil for unexpected good to sprout in.