Seamus Heaney on W.B. Yeats:
"Reading Yeats, we are under the sway of a voice that offers both expansiveness and containment, and this is as true of the early work as it is of a magnificient late set-piece such as 'A Dialogue of Self and Soul.' The expansiveness arises from a confidence that the mind is its own place and within it great distances can be imagined and traversed at will. The containment is present as a sensation of strong emotional and intellectual pressure coming up against formal limits and straining within them."