I f thou must love me, let it be for nought Except for...

I f thou must love me, let it be for nought Except for love's sake only. Do not say, I love her for her smile ... her look ... her way Of speaking gently ... for a trick of thought That falls in well with mine, and, certes, brought A sense of pleasant ease on such a day- For these things in themselves, Beloved, may Be changed, or change for thee-and love so wrought, May be unwrought so.