The book you are referring to is "Course in General Linguistics" which was compiled and edited from Saussure's lecture notes by his students after his death in 1913. The book was published in 1916 and is considered a foundational text in the field of structuralist linguistics.
Key concepts in "Course in General Linguistics":
* Langue vs. Parole: Saussure distinguished between the abstract system of language (langue) and its actual use (parole).
* Signifier vs. Signified: A linguistic sign consists of a signifier (the sound or written form) and a signified (the concept it represents).
* Synchronic vs. Diachronic: He emphasized the importance of studying language at a specific point in time (synchronic) rather than focusing on its historical development (diachronic).
* Paradigm vs. Syntagm: Language is organized based on relationships between words (paradigm) and the order of words in a sentence (syntagm).
* Arbitrariness of the Sign: Saussure argued that there is no inherent relationship between the signifier and the signified.
"Course in General Linguistics" is considered a complex and often debated text, but it remains essential reading for anyone interested in linguistics and the study of language.