Equilibrium is the profoundest tendency of all human activity.

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

In other words, knowledge of the external world begins with an immediate utilisation of things, whereas knowledge of self is stopped by this purely practical and utilitarian contact.

Play is the work of childhood.

The most developed science remains a continual becoming

How can we, with our adult minds, know what will be interesting? If you follow the child...you can find out something new.

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.