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

Play is the answer to how anything new comes about.

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

The current state of knowledge is a moment in history, changing just as rapidly as the state of knowledge in the past has ever changed and, in many instances, more rapidly.

To understand is to invent.

Logic and mathematics are nothing but specialised linguistic structures.

I have always detested any departure from reality, an attitude which I relate to my mother's poor mental health.