At the start of the 19th century, the field we now call psychology was still the branch of philosophy that studied the soul. How did psychology come to define itself as a separate area of inquiry, and how did it come to be a science? In Wundt, Avenarius and Scientific Psychology: A Debate at the Turn of the Twentieth Century
(Palgrave MacMillan 2019), Chiara Russo Krauss
considers the conceptual foundations of psychology as a science in the conflicting views of Wilhelm Wundt and Richard Avenarius. Wundt established the first psychology lab but continued to see psychology as a science of self-observation, while the philosopher Avenarius embraced the emerging materialistic perspective in which the same physical methods that had just been successfully applied to explaining life could be used to explain conscious experience. Russo Krauss, a researcher at the University of Naples Federico II, makes clear the major role that Avenarius played in the shaping of psychology into the science that it is today.