Physician is a general term for a doctor of medicine, someone legally qualified to practice medicine. The term is often employed to refer to anyone engaged in the general practice of medicine as distinguished from such specialists as surgeons, ophthalmologists, and pediatricians. All qualified physicians are doctors of medicine, but not all doctors practice medicine. Doctor refers to anyone who has been granted a doctor's degree. There are doctors of dentistry, veterinary science, philosophy, the arts, letters, literature, science, and many other disciplines.
Dictionary of problem words and expressions. Harry Shaw. 1975.