Hippocrates is particularly right if there are solid pieces of evidence that ‘to do nothing’ is the best and the most effective option of them all. Developing, trying and evaluating new treatment methods (as well as older drugs and practices, that have not been evaluated and understood the way we do so today) is one of the most invaluable ways to produce and use the best evidence of what is good, less good, and bad for an individual patient as well as for groups of individuals representing a community. This chapter is simply a summary of our current ever-increasing experience.