a restless animal..........................

     The ideal of static perfection, which Plato derived from Parmenides and embodied in his theory of ideas, is one which is now generally recognised as inapplicable to human affairs.  Man is a restless animal, not content, like the boa constrictor, to have a good meal once a month and sleep the rest of the time.  Man needs, for his happiness, not only the enjoyment of this or that, but hope and enterprise and change.

-Bertrand Russell,  Philosophy And Politics