In his 1928 main work "The Logical Structure of the World," Rudolf Carnap attempted to support the epistemological thesis of English empiricism, which posits that the foundation of all our knowledge of reality lies in perceptual experiences, through the methodical and logically insightful construction of the world of objects from such specific elemental experiences. What was new and groundbreaking about this approach was Carnap's use of the tools of modern logic—he was a student of Frege—especially the relational logic developed by Russell, and the consideration of the psychological insight that simple sensory data are not experiences but must be inferred from experiences in a backward manner.