The Shaking of the Foundations by Paul Tillich
 
A collection of twenty-two philisophical sermons by existentialist theologian Paul Tillich, crossing multiple historical and cultural influences; Marx, Buddha, Nietzsche, the Ancient Greeks, Rilke, Kierkegaard and Jesus of Nazareth all play a part in Tillich’s apologetic sermons, based on Biblical texts, which are characterised by a width and modernity of knowledge that permits him, if need be, to comment with terrifying irony on the groundless existence of contemporary life.