The New Poetry's, most remembered phrase is the ‘new seriousness’, a phrase which may sound urgent and understandable at first reading, but which is situated within a complex web of debts and implications. ‘Seriousness’ has both commonplace currency and a distinguished heritage in the critical tradition, in part because the word has served to translate into English a term from one of the earliest and most important works in that tradition. Matthew Arnold writes in ‘The Study of Poetry’:

Translating Aristotle into English and into an Arnoldian Victorian, Arnold makes seriousness connect to ‘truth’, and this in turn to an appropriate diction. ‘Seriousness’ becomes a loaded term which inclines towards certain presuppositions of what does and does not merit the highest praise; a lack of grave dignity, too much of a sense of humour perhaps, may debar even Chaucer from poetry's top rank: ‘The substance of Chaucer's poetry, his view of things and his criticism of life, has largeness, freedom, shrewdness, benignity; but it has not this high seriousness, which Aristotle assigns as one of the grand virtues of poetry.’

The transition from σπουδαιότερον to ‘seriousness’ involves the employment of a word which, as well as meaning ‘weighty, important’, will, in common usage and OED definition, signify ‘expressing or arising from earnest purpose’, ‘of grave or solemn disposition or character’, ‘not light or superficial’ and that which is routinely opposed to the joking or the humorous. These meanings are not so easy to untangle: often one meaning will imply others, and the user of the word, even if primarily employing one sense, will be glad of or hampered by other connotations.