Punishment renders autonomy of conscience impossible.
Scientific knowledge is in perpetual evolution; it finds itself changed from one day to the next.
True interest appears when the self identifies itself with ideas or objects, when it finds in them a means of expression and they become a necessary form of fuel for its activity.
We learn more when we are compelled to invent.
Logic and mathematics are nothing but specialised linguistic structures.
In genetic epistemology, as in developmental psychology, too, there is never an absolute beginning.