The practice of narrative and argument does not lead to invention, but it compels a certain coherence of thought.

Logical reasoning is an argument which we have with ourselves and which reproduces internally the features of a real argument.

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

During the earliest stages of thought, accommodation remains on the surface of physical as well as social experience.

Play is the answer to the question, 'How does anything new come about?'

Before playing with his equals, the child is influenced by his parents. He is subjected from his cradle to a multiplicity of regulations, and even before language he becomes conscious of certain obligations.