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.

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

Moral autonomy appears when the mind regards as necessary an ideal that is independent of all external pressures.

Children have real understanding only of that which they invent themselves, and each time that we try to teach them too quickly, we keep them from reinventing it themselves.

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

Reflective abstraction, however, is based not on individual actions but on coordinated actions.

Experience precedes understanding.