The idea that the world as it is now the worst that could be. It is the belief that things are bad and likely to get worse, or that evil will eventually win over good. It is the opposite of optimism, which is the belief that things are good and will get better.

A common problem that shows the difference between optimism and pessimism is the question, “Is the glass half empty or half full?” Most people think that optimists will say “half full” and pessimists will say “half empty,” but this isn’t always the case.