This advance, however, has caused Alzheimer's disease to be far more common than it used to be. I would argue that the population of major problems is almost static, that most of the large problems and challenges of the human condition have been with us for thousands of years. Besides logic there is also historical support for optimism. Pessimists and doomsayers have been with us throughout history. Every kind of catastrophe imaginable has been predicted and practically none have come to pass.
Society keeps on muddling through.
One popular doomsayer is Paul Erlich. Repeatedly, Erlich's predictions have failed to materialize. Strangely, people keep buying his books and listening to what he says. Pessimism's only real advantages are that, in the short run, it's easier to be pessimistic than optimistic, and cynicism is the cheapest way to act sophisticated. The greatest damage done by pessimism is what it does to our youth.