These works, as the sub-title makes clear, are unfinished sketches for Philosophical Investigations, possibly the most important and influential philosophical work of modern times. The 'Blue Book' is a set of notes dictated to Witgenstein's Cambridge students in 1933-1934: the 'Brown Book' was a draft for what eventually became the growth of the first part of Philosophical Investigations. This book reveals the germination and growth of the ideas which found their final expression in Witgenstein's later work. It is indispensable therefore to students of Witgenstein's thought and to all those who wish to study at first-hand the mental processes of a thinker who fundamentally changed the course of modern philosophy. 邦題　『青色本』　（ちくま学芸文庫）「語の意味とは何か？」本書はこの端的な問いかけから始まる。青い表紙で綴じられていたために『青色本』と名付けられた、ウィトゲンシュタインの講義録。 11月14日朝日新聞・朝刊「広告欄 」に掲載