On MDs and PhDs and Professors

In the 1950s, my father received a PhD in Mathematics, and his brother went to medical school and got an MD. Later, their mother was often heard to say that two of her children were doctors, but only one was a real doctor (and she meant my uncle, not my father). My variation on the issue of titles involves "professor": as I have never actually held an appointment with that title, so when people call me "Professor Shields", I tell them that if they want want to use a title in speaking or writing to me, they can call me Dr. Shields, because I do have a PhD in Comparative Literature. (Andrew Shields, #111words, 13 December)