The current state of knowledge is a moment in history, changing just as rapidly as the state of knowledge in the past has ever changed and, in many instances, more rapidly.

Our problem, from the point of view of psychology and from the point of view of genetic epistemology, is to explain how the transition is made from a lower level of knowledge to a level that is judged to be higher.

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

To express the same idea in still another way, I think that human knowledge is essentially active.

Logic and mathematics are nothing but specialised linguistic structures.

Only education is capable of saving our societies from possible collapse, whether violent, or gradual.

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.