Here's a discussion of a parallel issue: scientific regress. What's interesting about the account of the loss of knowledge about how to prevent scurvy is (1) how rare these regresses are, (2) how easy it is with the benefit of hindsight to point to the scientific errors that caused the regression. In short, there's a one-way ratchet on scientific knowledge because the external facts constrain the viability of different scientific beliefs.
But if you look earlier in history we see much clearer and common examples of technological and even scientific regress. See the loss of technology and science that occured with the decline of Roman civilization or the Greek dark age over a millenium earlier.
I don't really count the fall of the Roman empire as scientific regress. And even if it does count, that's before the scientific method was well established, so there every reason to think that institutions would fail at preserving knowledge.
Regardless, possible constraints created by "moral facts" didn't go away just because any particular government or society fell. The sack of Rome didn't (or at least shouldn't) cause farmers in the middle of nowhere to change their beliefs about the moral correctness of beating their slaves in particular circumstances. Changing circumstances != changing moral beliefs.
Related to: Voting is like donating thousands of dollars to charity, Does My Vote Matter?
And voting adds legitimacy to it.
Thank you.
#annoyedbymotivatedcognition