A study on the use of stents to treat a certain kind of stroke recently caught Dalrymple’s eye:

One little phrase caught my attention.

The doctors who took part in the trial had to have performed the stenting procedure using the latest technology and appliances at least five times before they were allowed to participate in it. This meant that many procedures must have been performed previously without knowing whether or not they would benefit the patients. From the point of view of current rigorous medical ethics, those procedures were probably unethical, though not of course meant maliciously. Perhaps there is an inevitable tension between medical advance and medical ethics.