Great post, food for thought. I sometimes distinguish between beliefs and impressions, but should do so more.

If ideas change incrementally by mutation, and the average false idea does more damage than the truth, and as ideas get closer to the truth they trend noisily toward doing less damage, is that a general moral argument against spreading and believing specific false ideas that seem beneficial (both because the neighbors of beneficial-seeming false ideas regress to a more damaging mean than the neighbors of the truth, and because the truth gains some stability against mutations by being the truth)?