Thought is not merely expressed in words, it comes into existence through them

Learning is more than the acquisition of the ability to think; it is the acquisition of many specialized abilities for thinking about a variety of things.

Childhood is a complex dialectical process characterized by periodicity, unevenness in the development of different functions, metamorphosis or qualitative transformation of one form into another, intertwining of external and internal factors, and adaptive processes which overcome impediments that the child encounters.

What children can do with the assistance of others might be in some sense even more indicative of their mental development than what they can do alone

Any human act that gives rise to something new is referred to as a creative act, regardless of whether what is created is a physical object or some mental or emotional construct that lives within the person who created it and is known only to him.

In play, the child is always behaving beyond his age, above his usual everyday behaviour; in play he is, as it were, a head above himself. Play contains in a concentrated form, as in the focus of a magnifying glass, all developmental tendencies; it is as if the child tries to jump above his usual level.

The true direction of the development of thinking is not from the individual to the social, but from the social to the individual.