Through others we become ourselves.

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 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.

There is reason to believe that voluntary activity, more than highly developed intellect, distinguishes humans from the animals which stand closest to them.

What a child can do today with assistance, she will be able to do by herself tomorrow.

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

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.