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

Knowing reality means constructing systems of transformations that correspond, more or less adequately, to reality.

Children require long, uniterrupted periods of play and exploration

Are we forming children who are only capable of learning what is already known? Or should we try to develop creative and innovative minds, capable of discovery from the preschool age on, throughout life?

It was while teaching philosophy that I saw how easily one can say ... what one wants to say. ... In fact, I became particularly aware if the dangers of speculation ... It's so much easier than digging out the facts. You sit in your office and build a system. But with my training in biology, I felt this kind of undertaking precarious.

We learn more when we are compelled to invent.

Chance... in the accommodation peculiar to sensorimotor intelligence, plays the same role as in scientific discovery. It is only useful to the genius and its revelations remain meaningless to the unskilled.