Saussure's Cours de linguistique générale occupies a place of unique importance in the history of Western thinking about man in society. It is a key text not only within the development of linguistics but also in the formation of that broader intellectual movement of the twentieth century known as ‘structuralism’. With the sole exception of Wittgenstein, no thinker has had a profound an influence on the modern view of homo loquens as Saussure.
[From Roy Harris' "Translator's Introduction" (1986/1997: [ix])]

Ferdinand de Saussure's criticism of the inadequate tenets and methods characteristic of the linguistics which prevailed during the period of his own intellectual development we heard from his own lips on many occasions. All his life he pursued a determined search for guiding principles to direct the course of his thinking through that chaos. But it was not until 1906, when he had succeeded Joseph Wertheimer at the University of Geneva, that he was able to expound his own views. They were the mature product of many years' reflexion. He gave three courses of lectures on general linguistics, in 1906–1907, 1908–1909, and 1910–1911. The requirements of the curriculum, however, obliged him to devote half of each course to a historical and descriptive survey of the Indo-European languages, and the essential core of his subject was thus considerably reduced.
[From Charles Bally and Albert Sechehaye's "Preface to the First Edition" (1916/1997: [xvii])]

The science which has grown up around linguistic facts passed through three successive phases before coming to terms with its one and only true object of study.
[From "A Brief Survey of the History of Linguistics", chapter 1 of Ferdinand de Saussure's Course in General Linguistics (1916/1997: [1])]