That isn't what Diamond says at all! What he does is explain that the reason social scientists talk about trouble so often is the same reason doctors talk mostly about disease, rather than wellness: We want to understand the problem areas better, so we can intervene to fix or improve the causes. We aren't trouble-addicts; we're optimists. The same argument should be repeated by leftists. We complain because we are trying to find ways to do better, not because we're gloom addicts.
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Precisely right.
Diamond is trying to sensibly come to grips with the limitations of human thinking, our tendency to do short-sighted and destructive things, even self-destructive things. Not to wallow in woe, but provide a method for correction - a latter day project reminiscent of Spinoza's efforts to identify common errors so we might improve our understanding.
For the curious, I recommend Diamond's essay WHY DO SOME SOCIETIES MAKE DISASTROUS DECISIONS? available here -
<http://www.edge.org/3rd_culture/diamond03/diamond_p2.html
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