The lesson of history.
D002170:Canada; D003695:Delivery of Health Care; D005060:Europe; D049668:History, 15th Century; D049669:History, 16th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049691:History, Medieval; D006761:Hospitals / Q000266:history; D008505:Medical Staff, Hospital