Helmholtz is reported to have said of some of Wundt's experiments that they were schlampig (sloppy). Comparing Wundt to Helmholtz, who was a careful experimentalist and productive researcher, one must conclude that Wundt's most important contributions were as a systematizer, organizer, and encyclopedist. William James considered Wundt "only a rather ordinary man who has worked up certain things uncommonly well."
Wundt's Grundriss der Psychologie (1896; Outline of Psychology) was a less detailed treatment than his Principles, but it contained the new theory of feeling. A popular presentation of his system of psychology was Einführung in die Psychologie (1911; Introduction to Psychology). His monumental Völkerpsychologie (1912; Folk Psychology), a natural history of man, attempted to understand man's higher thought processes by studying language, art, mythology, religion, custom, and law. Besides his psychological works he wrote three philosophical texts: Logic (1880-1883), Ethics (1886), and System of Philosophy (1889). Wundt died near Leipzig on Aug. 31, 1920.