In this new study Edward Larrissy seeks to examine the relationship between Yeats's divided Anglo-Irish inheritance and his aesthetic. The difference in the title is primarily cultural difference, but it does also refer to deconstructionist differance as providing one possible way of thinking about the acute sense of division palpable in Yeats's poems at the very point where he seeks unity of being.

In pursuit of these topics Larrissy seeks to illustrate an overall movement in Yeats's work: initially, Yeats thought of himself as an intermediary between Eternal Beauty, which has Celtic affinities, and measure which may be mechanical if not handled correctly and hence is associated with the cosmopolitan or English. This fresh examination of his major poems owes much to modern critical theory, with a study of the poet's historical position showing the strength of Gaelic influences upon him.

When Yeats starts to celebrate his Anglo-Irish ancestry, reacting against his own early work, he also begins to feel more marginal to the development of Irish society and there is a corresponding tendency to value qualities of firm outline in his poetry which had earlier been seen as too sternly measured and 'external'. In his last phase, however, these tensions soften and merge, and both passion and measure are seen as triumphant possessions of the whole Irish tradition.

This book also offers new insights about Yeats's relationship to the Romantic poets, to freemasonry and the later Gaelic tradition. It also looks in detail at the influence of Blake and the esoteric language of 'contrariety' and 'outline' which provided Yeats with the vocabulary of self-understanding.