The artist penetrates the concrete world in order to find at its depths the image of its source, the image of ultimate reality. According to Greeley aspects of the Catholic imagination include community, salvation, hierarchy, sacred place/sacred time, and sacred desire. As one reviewer of Greeley's book noted:  The cultural works include the Cologne Cathedral, Bernini's "St. Theresa in Ecstasy", Marian poems by Gerard Manley Hopkins and François Villon, Italian American films (especially those directed by Martin Scorsese), James Joyce's "Ulysses", "The Power and the Glory" by Graham Greene, the slow movement from Mozart's Piano Concerto no. 26, Verdi's "La Traviata", St. Xavier del Bac Mission, and Lars von Trier's motion picture, "Breaking the Waves". In "The Catholic Imagination" (2000), Greeley's aim is to "specify how the Catholic imaginative tradition differs from other versions of the Western Christian story." It informs its research through the work of David Tracy, especially "The Analogical Imagination: Christian Theology and the Culture of Pluralism" (1981). This work suggests a strategy informed by an analogical imagination as an answer to the theological question of how to "form a new and inevitably complex theological strategy that will avoid privatism" in religious discourse that embraces pluralism. Greeley argues that the metaphor inherent in the Catholic imagination is indicative of the necessity to use metaphor in order to relate knowledge generally:Cognitive psychologists have recently begun to insist that metaphors – statements that one reality is like another reality – are the fundamental tools of human knowledge. We understand better and explain more adequately one reality to ourselves by comparing it to another reality which we already know. Tracy sees the tendencies of Catholic artists, writers, and theologians to emphasize a metaphorical discourse – and a way to know the world through analogy – versus a Protestant tendency to stress the disconnect inherent in metaphor, as in a dialectical imagination, which Tracy designates as "a necessary corrective to the analogical imagination." Greeley states:The love of God for [Catholics], in perhaps the boldest of all metaphors (and one with which the Church has been perennially uneasy), is like the passionate love between man and woman. God lurks in aroused human love and reveals Himself to us (the two humans first of all) through it. Contemporary art critic and art historian Eleanor Heartney addresses these interpretations of the Catholic imagination in her work "Postmodern Heretics: The Catholic Imagination in Contemporary Art", bringing to light the complex relationships underlying Catholicism's sacramental vision and the "physically provocative work it seems to inspire."