This book is a classic work of linguistics, created by one of the most prominent scholars, Otto Jaspersen. The linguistic importance of this book is attributed to the fact that it underlines the importance of the role of the speaker in the natural development of the language. The topics presented in this book include the history of linguistics pre and during the 19th century, the development of child language, the role of the speaker on language development, causes for the linguistic change, etymology, and language development.