Never give all the heart, for love Will hardly seem worth thinking of To passionate women if it seem Certain, and they never dream That it fades out from kiss to kiss; For everything that's lovely is But a brief, dreamy, kind delight. O Never give the heart outright, For they, for all smooth lips can say, Have given their hearts up to the play. And who could play it well enough If deaf and dumb and blind with love? He that made this knows all the cost, For he gave all his heart and lost.
To be the father of growing daughters is to understand something of what Yeats evokes with his imperishable phrase 'terrible beauty.' Nothing can make one so happily exhilarated or so frightened: it's a solid lesson in the limitations of self to realize that your heart is running around inside someone else's body. It also makes me quite astonishingly calm at the thought of death: I know whom I would die to protect and I also understand that nobody but a lugubrious serf can possibly wish for a father who never goes away.
What can be explained is not poetry.
Mad Ireland hurt you into poetry.
Yeats was 18th-century oratory, almost.