Why It Is Appropriate to Address Someone with a Ph.D. as “Doctor”
Ph.D. stands for “Doctor of Philosophy.” To earn this degree, one must make an original contribution to humanity’s body of knowledge (In ancient Greek, “philosophy” means “lover of wisdom”). It is an extraordinary feat, taking years of dedicated study at graduate school. The course of study culminates in the candidate writing and defending a thesis dissertation, which must be approved by more senior experts in the chosen discipline (history, education, biology, etc.).
M.D. stands for “Doctor of Medicine” and refers to a physician. It is another extraordinary achievement that involves years of detailed study and training. After four years of medical school, candidates apply for a residency program to become further trained in their chosen medical specialty. Candidates also have to pass rigorous exams in their country, such as the United States Medical Licensing Examination (USMLE). I’ve heard some people suggest that an M.D. degree is like a “Ph.D. in Medicine.”
Ph.D. = work on a body of knowledge
M.D. = work on your body
Ph.D. and M.D. are the highest university degrees one can attain. Some people earn both Ph.D. and M.D. degrees (M.D./Ph.D.) and practice both medicine and research. They are sometimes referred to as physician-scientists.
The term “doctor” is in the name of each degree, and it is customary to address individuals who have earned these credentials as “Doctor” if they so choose. The designation not only highlights their accomplishments but also signals to others that they are an authority in their field. In fact, the word “doctor” is derived from a Latin word that means “to teach,” meaning that people who have earned either an M.D. or Ph.D. have attained a level of knowledge that positions them to be a teacher of that knowledge. Seeking guidance from those carrying these credentials can help us recognize experts so we can better navigate a world polluted with nefarious institutions spreading misinformation and pseudoscience with unprecedented ease.
In the U.S., many people generally assume that someone using the “Dr.” prefix is a medical doctor, but that is an incorrect assumption. If you are introduced to a “Dr. So-and-so” at a party, it is best to ask them about their field of study before you solicit their opinion about that weird mole on your neck.