Optimists and pessimists

[James A. Landau]

Aside from the quote about the glass that is half full/empty, there are
several other optimist-pessimist provers.  Two that come to mind:

An optimist thinks this is the best of all perfect worlds.  A pessimist is
afraid that it is.  (This one probably goes back a ways, possibly to Voltaire's
time).

[in Europe] the optimists are learning Russian and the pessimists are
learning Chinese.  (This one is obviously from the Cold War, and probably after the
Sino-Soviet split, say the early 1960's.)

A somewhat related proverb:  "A cyniic knows the price of everything and the
value of nothing."

    - Jim Landau