In this 1901 work, Berthold Delbrück (1842–1922), who is famous for his contribution to the study of the syntax in Indo-European languages, focuses on Wilhelm Wundt's understanding of speech. Wundt (1832–1920), often referred to as the 'father of experimental psychology', held that language was one of the most important aspects of mental processing. In order to account for Wundt's theories on the nature of the soul, and his belief that emotion and perception are acts of experience rather than objects, Delbrück compares Wundt's theories with those of psychologist and educationalist J. F. Herbart (1776–1841). Delbrück also pays attention to the explanation of such topics as the hand gestures used by actors (and the people of Naples), the sentence structure of the German language, and onomatopoeia, though he emphasises that he has not addressed those elements in Wundt's works which are founded in psychology rather than in grammar.
