Knowing reality means constructing systems of transformations that correspond, more or less adequately, to reality.

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

Knowing reality means constructing systems of transformations that correspond, more or less adequately, to reality.

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.

When you teach a child something you take away forever his chance of discovering it for himself.

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

We learn more when we are compelled to invent.