Matthew Arnold's term "high seriousness" describes the serious treatment of a subject in a way that is both grand and intense. He believed that this was the most important quality of great poetry.
Arnold used the term in his 1880 work The Study of Poetry, which is considered a key work in English literary criticism.
He believed that high seriousness was a sign of a poem's "higher truth" and that it was a key component of a poem's moral purpose.
Arnold believed that the best poetry was sincere and truthful, and that it could provide consolation for people.
He believed that poets like Homer, Dante, Shakespeare, and Milton were examples of high seriousness.
He believed that Geoffrey Chaucer lacked the high seriousness needed to be considered a classic.