Wundt gained important ideas and exploited them in an original way in his principles and methodology of empirical psychology : the principle of actuality, psychophysical parallelism, combination of causal and teleological analysis, apperception theory, the psychology of " striving ", i . e . volition and voluntary tendency, principles of epistemology and the perspectivism of thought.
42.
In his book " Scientific Perspectivism " he develops a version of perspectival realism in which he argues that scientific descriptions are somewhat like colours, in that they capture only selected aspects of reality, and those aspects are not bits of the world seen as they are in themselves, but bits of the world seen from a distinctive human perspective.
43.
B . J . Leggett construes Stevens's perspectivism as commitment to the principle that " instead of facts we have perspectives, none privileged over the others as truer or more nearly in accord with things as they are, although not for that reason all equal . " This principle that " underlies Nietzschean thought " is central to Leggett's reading.
44.
Reluctant to construct a systematic philosophy, this book comprises more a collection of debunkings of unwarranted assumptions than an interpretation and " contains the seeds of concepts crucial to Nietzsche's later philosophy, such as the need to transcend conventional Christian morality "; he uses his perspectivism and the idea of the will to power as explanatory devices, though the latter remains less developed than in his later thought.
45.
MacIntyre's account also defends three further theses : first, that all rational human inquiry is conducted whether knowingly or not from within a tradition; second, that the incommensurable conceptual schemes of rival traditions do not entail either relativism or perspectivism; third, that although the arguments of the book are themselves attempts at universally valid insights they are nevertheless given from within a particular tradition ( that of Thomist Aristotelianism ) and that this need not imply any philosophical inconsistency.
46.
It was Protagoras who claimed that " man is the measure of all things, of the things that are, that they are, and of the things that are not, that they are not, " which Plato interprets as a radical perspectivism, where some things seem to be one way for one person ( and so actually are that way ) and another way for another person ( and so actually are " that " way as well ); the conclusion being that one cannot look to nature for guidance regarding how to live one's life.
47.
German philosophy is historically significant : Gottfried Leibniz's contributions to rationalism; the enlightenment philosophy by Immanuel Kant; the establishment of classical German idealism by Johann Gottlieb Fichte, Georg Wilhelm Friedrich Hegel and Friedrich Wilhelm Joseph Schelling; Arthur Schopenhauer's composition of metaphysical pessimism; the formulation of communist theory by Karl Marx and Friedrich Engels; Friedrich Nietzsche's development of perspectivism; Gottlob Frege's contributions to the dawn of analytic philosophy; Martin Heidegger's works on Being; the development of the Frankfurt school by Max Horkheimer, Theodor Adorno, Herbert Marcuse and J�rgen Habermas have been particularly influential.
