If optimism shapes reality, and helps people progress more quickly, and if progress has brought improvements in health, lifespan, happiness, equality, and a host of other measures that matter, then more optimism is good.

Criticism is crucial, but pessimism – “a tendency to see the worst aspect of things or believe that the worst will happen; a lack of hope or confidence in the future” – is actively harmful on both individual and societal levels.

Optimism is the meta that defines the rate of progress, and progress translates into longer, healthier, wealthier, and happier lives for more people.