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.

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 teacher must adopt the role of facilitator not content provider.

Every function in the child's cultural development appears twice: first, on the social level, and later, on the individual level; first, between people (interpsychological) and then inside the child (intrapsychological). This applies equally to voluntary attention, to logical memory, and to the formation of concepts. All the higher functions originate as actual relationships between individuals.

It may be said that the basic characteristic of human behavior in general is that humans personally influence their relations with the environment and through that environment personally change their behavior, subjugating it to their control.

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

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