"In the process of development the child not only masters the items of cultural experience but the habits and forms of cultural behaviour, the cultural methods of reasoning. We must, therefore, distinguish the main lines in the development of the child's behaviour. First, there is the line of natural development of behaviour which is closely bound up with the processes of general organic growth and the maturation of the child. Second, there is the line of cultural improvement of the psychological functions, the working out of new methods of reasoning, the mastering of the cultural methods of behaviour. (Vygotsky, 1994, pg. 57)

"We have many reasons to assume that the cultural development consists in mastering methods of behaviour which are based on the use of signs as a means of accomplishing any particular psychological operation. This is not only proved by the study of the psychological development of primitive man, but also by the direct and immediate observation of children. (Vygotsky, 1994, pg. 58)

"The most important stage in the development of reasoning and speech is the transition from external to internal speech." (Vygotsky, 1994, pg. 68)

"No development--that of the child included--in the condition of modern civilized society can be reduced merely to the development of natural inborn processes and the morphological changes conditioned by the same; it includes, moreover, that social change of civilized forms and methods which help the child in adapting itself to the conditions of the surrounding civilized community." (Luria, 1994, pg. 46)

"Along with the purely external methods which help the child in solving different problems, we must recognize the existence of a huge number of internal methods and habits evolved in school and which are due to character and surroundings; we place under this head all the child's habits connected with speech, thought, logic; in short, using the expression of Claparède, the whole of his 'inner technique'. (Luria, 1994, pg. 48)

"In the course of investigation of the child's behaviour we came to the conclusion that it passes through several stages, each of them differing in quality. We can mention roughly the following stages:

1. The child is not in a state to perform the task by the complicated auxiliary means. He is incapable of connoting the objects offered as the auxiliary means and fails to remember a series of words 'with the aid' of cards; such as the pre-instrumental stage of development.

2. The child begins to attempt to use the objects offered as the means for attaining the object, but does it clumsily, without attempting to establish a rational connection between the task and the auxiliary means, looking at the latter as a sort of magic....

3. Finally, much later, we observe the real instrumental stage in the development of the child, the main features of which are the complicated structure of acts of behaviour, the ability to adapt one's self to difficult tasks by using adequate means and the outer auxiliary stimuli. It is precisely this part of behaviour which develops most in a schoolboy and the modern civilized man, and is of utmost significance." (Luria, 1994, pg. 54-55)