During the 17th century, according to Eliot's hypothesis, a gap opened up in Western culture between thought and feeling. This was largely a by-product of the dawning of the Age of Reason, the birth of the Scientific Revolution. Prior to this epoch, there was no such separation. Great poets, artists, and thinkers thought their feelings and felt their thoughts. This was the heyday of Christian humanism in which Christianity was combined with the insights of classical thought to provide an all-encompassing intellectual and cultural synthesis.
In relation to poetry, Eliot values the work of the Metaphysicals such as Donne because he sees it as epitomizing the fusion of intellect and feeling that characterized cultural life prior to the Age of Reason. As both a man of faith and an artist, Eliot regards the dissociation of sensibility—the separation between emotion and intellect affected by the Scientific Revolution—as a regrettable development, one that instantiated a limited, positivistic, one-dimensional view of human life that failed to do justice to the complexity of man's true nature.