Why is it that doctors call what they do “practice”?

Question: Why is it that doctors call what they do "practice"?
- Keywords:
  doctor,
  medicine,
  practice,
  work
Asked by finlay to Cathal, Daphne, Darren, Jon, Katherine on 15 Mar 2012.
- Cathal Breen answered on 15 Mar 2012:
  
  Diagnosing or looking after someone is a physical task therefore you practice medicine on people. To listen to someones heart you have to use a stethescope and place it on the persons chest. It takes practice and expertise to be able to do this.

Question: Why is it that doctors call what they do "practice"?