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

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

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

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

Logical positivists have never taken psychology into account in their epistemology, but they affirm that logical beings and mathematical beings are nothing but linguistic structures.

Teaching means creating situations where structures can be discovered.

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