category mistakes as discussed by Nicolai Hartmann. In this regard, Wundt created the first genuine epistemology and methodology of empirical psychology (the term philosophy of science did not yet exist). Apperception Apperception is Wundt's central theoretical concept. Leibniz described apperception as the process in which the elementary sensory impressions pass into (self-)consciousness, whereby individual aspirations (striving, volitional acts) play an essential role. Wundt developed psychological concepts, used experimental psychological methods and put forward neuropsychological modelling in the frontal cortex of the brain system – in line with today's thinking. Apperception exhibits a range of theoretical assumptions on the integrative process of consciousness. The selective control of attention is an elementary example of such active cognitive, emotional and motivational integration. Development theory of the mind The fundamental task is to work out a comprehensive development theory of the mind – from animal psychology to the highest cultural achievements in language, religion and ethics. Unlike other thinkers of his time, Wundt had no difficulty connecting the development concepts of the humanities (in the spirit of Friedrich Hegel and Johann Gottfried Herder) with the biological theory of evolution as expounded by Charles Darwin. Critical realism Wundt determined that "psychology is an empirical science co-ordinating natural science and humanities, and that the considerations of both complement one another in the sense that only together can they create for us a potential empirical knowledge." He claimed that his views were free of metaphysics and were based on certain epistemological presuppositions, including the differentiation of subject and object in the perception, and the principle of causality. With his term critical realism, Wundt distinguishes himself from other philosophical positions. Definition of psychology Wundt set himself the task of redefining the broad field of psychology between philosophy and physiology, between the humanities and the natural sciences. In place of the metaphysical definition as a science of the soul came the definition, based on scientific theory, of empirical psychology as a psychology of consciousness with its own categories and epistemological principles. Psychology examines the "entire experience in its immediately subjective reality." The task of psychology is to precisely analyse the processes of consciousness, to assess the complex connections (psychische Verbindungen), and to find the laws governing such relationships. Psychology is 'not a science of the individual soul . Life is a uniform mental and physical process that can be considered in a variety of ways in order to recognise