his comprehensive research programme on a development theory of the human intellect, now seen as an interdisciplinary or trans-disciplinary project. Misunderstandings of basic terms and principles Wundt's terminology also created difficulties because he had – from today's point-of-view – given some of his most important ideas unfortunate names so that there were constant misunderstandings. Examples include: physiological psychology – specifically not a scientific physiological psychology, because by writing the adjective with a small letter Wundt wanted to avoid this misunderstanding that still exists today; for him it was the use of physiological aids in experimental general psychology that mattered. Self-observation – not naive introspection, but with training and experimental control of conditions. Experiment – this was meant with reference to Francis Bacon – general, i.e. far beyond the scientific rules of the empirical sciences, so not necessarily a statistically evaluated laboratory experiment. For Wundt psychological experimentation primarily served as a check of trained self-observation. Element – not in the sense of the smallest structure, but as a smallest unit of the intended level under consideration, so that, for example, even the central nervous system could be an "element". Völkerpsychologie – cultural psychology – not ethnology. Apperception – not just an increase in attention, but a central and multimodal synthesis. Voluntaristic tendency, voluntarism – not an absolute metaphysical postulate, but a primary empirically-psychologically based accentuation of motivated action against the intellectualism and cognitivism of other psychologists. A representation of Wundt's psychology as 'natural science', 'element psychology' or 'dualistic' conceptions is evidence of enduring misunderstandings. It is therefore necessary to remember Wundt's expressly stated desire for uniformity and lack of contradiction, for the mutual supplementation of psychological perspectives. Wundt's more demanding, sometimes more complicated and relativizing, then again very precise style can also be difficult – even for today's German readers; a high level of linguistic competence is required. There are only English translations for very few of Wundt's work. In particular, the Grundzüge der physiologischen Psychologie expanded into three volumes and the ten volumes of Völkerpsychologie, all the books on philosophy and important essays on the theory of science remain untranslated. Such shortcomings may explain many of the fundamental deficits and lasting misunderstandings in the Anglo-American reception of Wundt's work. Massive misconceptions about Wundt's work have been demonstrated by William James, Granville Stanley Hall, Edward Boring and Edward Titchener as well as among many later authors. Titchener, a two-year resident of