So optimism’s benefits are not unbounded. Pessimism has a role to play, both in society at large and in our own lives; we must have the courage to endure pessimism when its perspective is valuable. What we want is not blind optimism but flexible optimism—optimism with its eyes open. We must be able to use pessimism’s keen sense of reality when we need it, but without having to dwell in its dark shadows.
