... People with great passions, people who accomplish great deeds, people who possess strong feelings, even people with great minds and a strong personality, rarely come out of good little boys and girls.

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

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

The only 'good' learning is that which is in advance of development.

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.

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

Language is the tool of the tools