Positive and negative thinking

From different, er, "spheres of discourse", but these two may be worth looking at side by side:

* Damien G Walter says Science fiction doesn't have to be gloomy, does it?

* Barbara Ehrenreich on The Power of Negative Thinking.

But Ehrenreich concludes:

When it comes to how we think, “negative” is not the only alternative to “positive.” As the case histories of depressives show, consistent pessimism can be just as baseless and deluded as its opposite. The alternative to both is realism — seeing the risks, having the courage to bear bad news and being prepared for famine as well as plenty. We ought to give it a try.