Scientific knowledge is in perpetual evolution; it finds itself changed from one day to the next.

I have always detested any departure from reality, an attitude which I relate to my mother's poor mental health.

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.

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.

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

The self thus becomes aware of itself, at least in its practical action, and discovers itself as a cause among other causes and as an object subject to the same laws as other objects.

Scientific thought, then, is not momentary; it is not a static instance; it is a process.