Every acquisition of accommodation becomes material for assimilation, but assimilation always resists new accommodations.

It is with children that we have the best chance of studying the development of logical knowledge, mathematical knowledge, physical knowledge, and so forth.

Intelligence is what you use when you don't know what to do.

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

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.

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

In genetic epistemology, as in developmental psychology, too, there is never an absolute beginning.