Guillen's poetry celebrates this life and things of this world. In Cantico, first published in 1928 and then substantially revised numerous times by the poet, he exalts the pure joy of being: "To be, nothing more. And that suffices." This enthusiasm for life was sustained until Clamor (three volumes published in 1957, 1960, and 1963), when the brutal realities of the modern world broke into his joyous vision. Even so, Guillen remained optimistic about the future, and in his poem Goodbye, Goodbye, Europe, he speaks of escaping the old decaying world to an "innocent new world," a reference to the United States where he taught in universities for many years. Guillen's style is concentrated, economical, disciplined and polished, showing the influence of classical forms as well as of the gongorist style. His is a "pure poetry" from which he has attempted to remove all nonpoetic elements, such as narrative and anecdote. He has translated Paul Valery and Paul Claudel into Spanish.