Theoretical thinking has never completely lost the
imagistic, puzzlelike qualities of the earliest
riddles. For example Archytas, the fourth-century-
B.C. philosopher and commander-in-chief of the city-
state of Tarentum (now in southern Italy), proved
that the universe had no limits by asking himself:
"Suppose that I came to the outer limits of the
universe. If I now thrust out a stick, what would
I find?"
Archytas thought that the stick must have projected
out into space. But in that case there was space
beyond the limits of the universe, which means that
the universe had no bounds. If Archytas's reasoning
appears primitive, it is useful to recall that the
intellectual experiments Einstein used to clarify to
himself how relativity worked, concerning clocks
seen from trains moving at different speeds, were
not that different.
Mihaly Csikszentmihalyi
Flow: The Psychology of Optimal Experience_ [1990], Chapter 6
