experimental psychologically based apperception psychology that included neuropsychological modelling. When Leibniz differentiates between two fundamental functions, perception and striving, this approach can be recognised in Wundt's motivation theory. The central theme of "unity in the manifold" (unitas in multitudine) also originates from Leibniz, who has influenced the current understanding of perspectivism and viewpoint dependency. Wundt characterised this style of thought in a way that also applied for him: "…the principle of the equality of viewpoints that supplement one another" plays a significant role in his thinking – viewpoints that "supplement one another, while also being able to appear as opposites that only resolve themselves when considered more deeply." Unlike the great majority of contemporary and current authors in psychology, Wundt laid out the philosophical and methodological positions of his work clearly. Wundt was against the founding empirical psychology on a (metaphysical or structural) principle of soul as in Christian belief in an immortal soul or in a philosophy that argues "substance"-ontologically. Wundt's position was decisively rejected by several Christianity-oriented psychologists and philosophers as a psychology without soul, although he did not use this formulation from Friedrich Lange (1866), who was his predecessor in Zürich from 1870 to 1872. Wundt's guiding principle was the development theory of the mind. Wundt's ethics also led to polemical critiques due to his renunciation of an ultimate transcendental basis of ethics (God, the Absolute). Wundt's evolutionism was also criticised for its claim that ethical norms had been culturally changed in the course of human intellectual development. Wundt's autobiography and his inaugural lectures in Zurich and Leipzig as well as his commemorative speeches for Fechner and his Essay on Leibniz provide an insight into the history of Wundt's education and the contemporary flows and intellectual controversies in the second half of the 19th century. Wundt primarily refers to Leibniz and Kant, more indirectly to Johann Gottlieb Fichte, Georg Wilhelm Friedrich Hegel, Friedrich Wilhelm Joseph Schelling and Arthur Schopenhauer; and to Johann Friedrich Herbart, Gustav Theodor Fechner and Hermann Lotze regarding psychology. In addition to John Locke, George Berkeley, David Hume and John Stuart Mill, one finds Francis Bacon, Charles Darwin and Charles Spencer, as well as French thinkers such as Auguste Comte and Hippolyte Taine, all of whom are more rarely quoted by Wundt. Metaphysics Wundt distanced himself from the metaphysical term soul and from theories about its structure and properties, as posited by Herbart, Lotze