Authors:

If it's working, keep doing it. If it's not working, stop doing it. If you don't know what to do, don't do anything.

Melvin Konner (1993). “Dear America: A Concerned Doctor Wants You to Know the Truth about Health Reform”, Addison Wesley Publishing Company
If it's working, keep doing it. If it's not working, stop doing it. If you don't know what to do, don't do anything.