Looks like I have to resume moderation.
Some of the comments border on flaming and will certainly evolve into the kind of name calling, insults, and invective that is counter productive. Most commeters have been very co-operative and the discussion flowed very nicely. I just want to express my appreciation for that. But I detect that one or two commenters are determined to break the commenting rules without any regard for others. In some cases the comments were so vile I had to delete them post facto. Others are borderline. Either way - I have no choice but to resume full moderation.
A new post will be up later today.