Play is the work of childhood.

In genetic epistemology, as in developmental psychology, too, there is never an absolute beginning.

How can we, with our adult minds, know what will be interesting? If you follow the child...you can find out something new.

I could not think without writing.

The more the schemata are differentiated, the smaller the gap between the new and the familiar becomes, so that novelty, instead of constituting an annoyance avoided by the subject, becomes a problem and invites searching.

Equilibrium is the profoundest tendency of all human activity.

Play is the answer to how anything new comes about.