[oldbrowser]

how can we rationally institute changes in our society?

"we" are not God.
"we" do not really understand all the dynamics involved.
"we" have a history of disastrous social engineering.
"we" should stick to what has brought us this far.

[rogerv]

I agree with what you have said, but not the conclusion you draw from it. We can do better than muddle along; that is why we have r&d. Modern medicine is much better than 19th century medicine because we have actively and aggressively sought better surgical technology and better drug therapies. And modern medicine would have been impossible without the studies in anatomy during the renaissance and breakthroughs in chemistry in the 19th century.