In this final excerpt (pt 1, pt 2, pt 3) Tolkien presents his son with wisdom sorely needed today: you almost certainly made a mistake when you married your partner who is, in fact, your real soul-mate. This is my favorite part of the letter and I suspect it will soon find its way into my pre-marital counseling.
Have a great V-Day weekend!
. . . Only a very wise man at the end of his life could make a sound judgment concerning whom, amongst the total possible chances, he ought most profitably to have married! Nearly all marriages, even happy ones, are mistakes: in the sense that almost certainly (in a more perfect world, or even with a little more care in this very imperfect one) both partners might have found more suitable mates. But the ‘real soul-mate’ is the one you are actually married to. You really do very little choosing: life and circumstance do most of it (though if there is a God these must be His instruments, or His appearances). It is notorious that in fact happy marriages are more common where the ‘choosing’ by the young persons is even more limited, by parental or family authority, as long as there is a social ethic of plain unromantic responsibility and conjugal fidelity.
But even in countries where the romantic tradition has so far affected social arrangements as to make people believe that the choosing of a mate is solely the concern of the young, only the rarest good fortune brings together the man and woman who are really as it were ‘destined’ for one another, and capable of a very great and splendid love. The idea still dazzles us, catches us by the throat: poems and stories in multitudes have been written on the theme, more, probably, than the total of such loves in real life (yet the greatest of these tales do not tell of the happy marriage of such great lovers, but of their tragic separation; as if even in this sphere the truly great and splendid in this fallen world is more nearly achieved by ‘failure’ and suffering). In such great inevitable love, often love at first sight, we catch a vision, I suppose, of marriage as it should have been in an unfallen world. In this fallen world we have as our only guides, prudence, wisdom (rare in youth, too late in age), a clean heart, and fidelity of will. . . .
-The Letters of J.R.R. Tolkien, No 43 ‘From a letter to Michael Tolkien 6-8 March 1941’