A William Butler Yeats Poem

God guard me from those thoughts men think
In the mind alone;
He that sings a lasting song
Thinks in a marrow-bone;

From all that makes a wise old man
That can be praised of all;
O what am I that I should not seem
For the song's sake a fool?

I pray, for word is out
And prayer comes round again,
That I may seem, though I die old,
A foolish, passionate man.