The Twitt @TellDrTell wondered:
I always wonder, when answering "highest lev. of ed. completed?" whether that is my PhD or my DVM or which is the right answer at the time.
— Rachel Tell (@TellDrtell) August 23, 2013
This brings up the question of what is meant by the "terminal degree", and this way of phrasing it focuses on one aspect of the concept, namely the "highest" degree.
For many fields of endeavor, some sort of degree that includes the word "Doctor" is the terminal degree. These ones are familiar to my audience.
- Doctor of Philosophy (PhD or DPhil if you are a Brit)
- Doctor of Medicine (MD)
- Doctor of Veterinary Medicine (DVM)
- Doctor of Dental Surgery (DDS)
These terminal degrees happen to predominate in our research fields and in the population of PIs who secure major grant awards. There are also others of potential interest to this audience, including
- Juris Doctor (JD. Did you know lawyers can call themself "Doctor"? Why don't they?)
- Doctor of Education (Ed.D.; fraught with implications)
- Doctor of Psychology (PsyD)
- Doctor of Pharmacy (PharmD)
If you hold only one Doctoral degree then presumably most folks would agree this is the highest one. But @TellDrTell wondered which to consider the highest one if a person holds two doctoral degrees.
Wikipedia and other sources tend to distinguish research degrees from professional degrees. In our usual pool of Doctoral letters, the Ph.D.s are research degrees and most of the other ones are professional degrees. This is underlined by the fact that most of the dual Doctoral degree subpopulation holds a PhD and one of the so-called professional degrees.
Being a research degree, obviously the PhD is higher, better and/or more terminal.
But wait. The Wikipedia lists a whole other bunch of research doctorates, like Doctor of Management and Doctor of Modern Languages, that you've never heard of and sound like some scam to avoid doing a Doctor of Philosophy in the respective subjects. In more familiar terms, there are PhDs in both Pharmacology and Psychology, so the PsyD and PharmD seem like lesser degrees to some folks. More limited.
Obviously those are lesser than the professional doctorates in Medicine, Dental Surgery, Veterinary Medicine and Juris. Wait, Juris? Is that law degree more "terminal" than a Ed.D. that was awarded after 6 years* of painstaking thesis research?
Okay, let's just say the Ph.D. is the best, all others are lesser and you should list your Ph.D. as your highest degree if you are also a M.D. or a D.V.M.
Unless you went to a combined M.D./Ph.D. program, in which case I think you are this, but not separately either a M.D. or a Ph.D.. And yes, unsurprisingly, I have heard at least one M.D., Ph.D. speak of how awesomely better this is than those lesser M.D./Ph.D. folks**.
And since it is usually a Doctor of Philosophy in [Subject], and the sciences are the most awesome, I think we can safely say that if you have two degrees in which one is a Ph.D. [Science] and the other is Ph.D. [Philosophy], the latter*** is the higher one. And you win the entire world's respect.
*I don't actually know the duration of Ed.D. programs.
**Gawd, I love academics.
***Because Philosophy squared