Reading Vygotsky's chapter on the ‘Development of scientific concepts’ (1987), it soon becomes apparent that it also contains a wealth of overlapping theoretical and conceptual ideas that Vygotsky attempts to draw together in order to clarify and explain the process of intellectual development. Concepts such as conscious awareness, imitation, instruction and the zone of proximal development are introduced and elaborated and Vygotsky uses them as resources to explore the relationship between development and instruction. Given the scope of the material covered in the chapter, it is not surprising that Luria, writing in his ‘Afterword’ to Thinking and Speech, comments (1987, p. 365) that this chapter ‘greatly broadens the conceptual framework of the whole of Vygotsky's work’ and ‘that it is in this chapter that the larger scope of Vygotsky's philosophical, psychological, and practical views are revealed’. But crammed into a single chapter, it makes for demanding reading. Not only is careful attention to the detail of text required but multiple readings are necessary to extract the various layers of meaning. The chapter is divided into eight sections and, like most of Vygotsky's texts, the introductory section provides a summary of the argument that is elaborated in the subsequent chapters.

The first translations into English of the book Thinking and Speech contain abridged versions of the chapters but, despite Luria's comments about the importance of the chapter as reflecting Vygotsky's thinking across a wide spectrum of views, it does not seem to have received the critical attention it deserves.