The distance between the actual developmental level as determined by independent problem solving and the level of potential development as determined through problem solving under adult guidance or in collaboration with more capable peers

Language is the tool of the tools

By giving our students practice in talking with others, we give them frames for thinking on their own.

The specifically human capacity for language enables children to provide for auxiliary tools in the solution of difficult tasks, to overcome impulsive action, to plan a solution to a problem prior to its execution, and to master their own behavior.

Psychology teaches us at every step that though two types of activity can have the same external manifestation, whether in origin or essence, their nature may differ most profoundly.

It is through others that we become ourselves.

Experience teaches us that thought does not express itself in words, but rather realizes itself in them