Van Wyck Brooks's Romantic expressionism was hostile to the classicism of "New Humanists" like Irving Babbitt and Paul Elmer More who had so profoundly influenced T. S. Eliot. His principal achievement came earlier, when his was the leading voice of the pioneering optimism that dominated the years from 1912 to 1917, the first phase of American Modernist experiment. The tags of decadence and despair stuck: Malcolm Cowley's The Second Flowering is subtitled "Works and Days of the Lost Generation". There had actually been two generations whose work had interfused to remarkable effect, interlocking the experimental formal and social optimism of first with the Spenglerian disillusion and historical pessimism of the second. Robert Frost seems to suggest that the old tradition of nature poetry is recoverable; a major part of his verse is, based on seasonal or natural lessons drawn from a natural world that seems to contain human significance.