The world of self-help teems with motivational quotes about the power of positive thinking, and the importance of reframing the negative. “Once you replace negative thoughts with positive ones, you’ll start having positive results.” “Positive thinking is more than just a tagline.” “There is nothing either good or bad, but thinking makes it so.” (That last one is from Shakespeare himself, via Hamlet.)Yet when it comes to the way in which we think and talk about the world outside our own heads, its future in particular, striking anything other than a very gloomy tone is not the done thing. We seem to have collectively decided that we must at all times pursue and project a sense of relentless, spirit-crushing pessimism. Not only will you sound careless and insensitive to all the suffering in the world if you say anything optimistic or upbeat, you will also find yourself lacking gravitas and just sounding deeply uncool.