True interest appears when the self identifies itself with ideas or objects, when it finds in them a means of expression and they become a necessary form of fuel for its activity.

What we see changes what we know. What we know changes what we see.

Every time we teach a child something, we keep him from inventing it himself. On the other hand, that which we allow him to discover for himself will remain with him visible for the rest of his life.

Every acquisition of accommodation becomes material for assimilation, but assimilation always resists new accommodations.

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.

The most developed science remains a continual becoming

Children require long, uniterrupted periods of play and exploration