This course traces the development of our understanding of living processes. It begins by considering in Plato’s time the spiritual properties ascribed to ‘life’. We see these naive interpretations as inevitable against the background of mysticism, vitalism and an absence of any formal understanding of physical processes. The development of Chemistry, Organic Chemistry, Physiology and Anatomy during the 19th century opens the door to demystification. The early twentieth century explodes with knowledge in these areas and enables our present understanding of living systems. Biochemistry, Enzymology, Molecular Biology and Cell Biology now underpin our view of the biological world. We follow the developments of these areas with selected examples. In the modern era much of this progress is marked by Nobel prizes. The personalities involved and their interrelationships are also a lesson in the role of personality in scientific discovery. Each lecture will have extensive opportunities for discussion and speculation. School Chemistry or Biology would help, but is not essential