According to Matthew Arnold, great poetry is defined by its truth, seriousness, and ability to interpret life. He believed that poetry is a "criticism of life" that uses poetic beauty and truth to address life's problems.
Truth
Arnold believed that great poetry must be true and sincere. He believed that poetry should be a representation of life without falsifying facts.
Seriousness
Arnold believed that great poetry must be serious in its application of ideas to life. He believed that poetry should be profound and noble.
Criticism of life
Arnold believed that poetry should interpret life and provide a moral purpose. He believed that poetry could provide a better understanding of life than philosophy, science, or religion.
Arnold believed that the greatest poets, such as Homer, Dante, and Milton, were able to achieve a high level of truth and seriousness in their work.