In most history of linguistics textbooks available until today Hermann Paul and his "Principles of Historical Linguistics," first published in 1880 and still available in reprints of the fifth edition of 1920, if given any attention at all, is cited for a statement he included in the second edition of 1886 in response to a review that had argued that in fact his book was a contribution to general linguistics that contained an argument in favor of a non-historical view of language. At the same time, while Paul was characterized as a positivist defender of historicism, a number of authors inside and outside of linguistics, Georg von der Gabelentz and Emile Durkheim among them, have been cited as prime precursors of Ferdinand de Saussure's "structuralist" ideas. The present paper is an attempt to show that, next to William Dwight Whitney whom Saussure referred to on several occasions in his Geneva lectures during 1907 and 1911, which formed the basis of the posthumous "Cours," Paul's "Prinzipien" should be regarded as an important source of Saussure's linguistic inspiration.