BOOK REVIEW 87 to other people. Owing to this, human activity absorbs the experience of mankind.' (Leontier) One can clearly discern a similarity in Vygotsky's idea of psychological tools or sign systems mediating human social processes and thinking to Marx's notion of how tools mediate overt human practical activity. In both cases, tools are not only used by humans to change the world, they also transform and regulate humans in this process. Since language is one of the key tools created by mankind for the organisation of thinking, Vygotsky was naturally drawn to study the relationship between language and thought. 'Language bears concepts that belong to experience and to the knowledge of humankind. Tools such as language have developed throughout history; the cultural condition joins the historical one,' in Vygotsky's work (G. Blanck). With his profound belief in the social determination of mental activity, Vygotsky illuminated the internalisation process. This for him is not simply the transferral of an external activity to a preexisting internal stage of consciousness but the process through which said internal stage is formed (Leontiev). Thus culture is not an entity independent of individuals with which they interact, as Blanck would put it, for Vygostsky, 'Humans are internalised culture'. Blanck sums Vygotsky's conceptualisation to imply that 'social relationships and culture are the sources of the mind, the working brain only its organ.' Since Vygotsky believed that higher mental functions are formed during children's enculturation, indissoluble link has to be found between his psychology and pedagogy. J.S. Bruner in his introduction to the first English edition of Thought and Language had pointed out: 'Vygotsky's conception of development is at the same time a theory of education'. Luis C. Moll observes that Vygotsky 'considered the capacity to teach and to benefit from instruction a fundamental attribute of human beings'. He rejected the idea of the innateness of psychological faculties. For him, children did not come into the world already equipped for the social world to elicit this inherent potential. Learning it not a sole performance. Learning and teaching is a creative process. Against Piaget, Vygotsky argued, 'The development of thought is, to Piaget, a story of the gradual socialisation of deeply intimate, personal, autistic mental states. Even social speech is represented as following, not preceding, egocentric speech. 'The hypothesis we propose reverses this course. . . We consider that the total development runs as follows. The primary function of speech, in both children and adults, is communication, social contact. The earliest speech of child is therefore essentially social. At first it is global and multi-functional; later its functions become differentiated. At a certain age the social speech of the child is quite sharply divided into egocentric and communicative speech. (We prefer to use the term communicative for the term of speech that Piaget calls socialised as