Logic and mathematics are nothing but specialised linguistic structures.

Play is the work of childhood.

The principal goal of education is to create men who are capable of doing new things, not simply of repeating what other generations have done-men who are creative, inventive, and discovers. The second goal of education is to form minds which can be critical, can verify, and not accept everything they are offered.

I could not think without writing.

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

This means that no single logic is strong enough to support the total construction of human knowledge.

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.