Gerd Theissen brings the newest and most illuminating theories of psychology to bear upon the writings of Paul to discover more of what Paul intends to say. In his introduction Theissen reflects upon the nature and usefulness of three theories of psychology: 'learning theory' (the study of aspects of religious beliefs, experiences and behaviour as things 'learned' from a surrounding culture), 'psychodynamics' (the study of aspects of religion to, the subsconscious human mind) and cognition' (the study of aspects of religion created by the human mind's rational interpretation of the world).