Good question. I think my reasons for doing a PhD were: (a) I was told that I wouldn’t progress in my intended career as a researcher unless I obtained one; (b) I was working on something that would be an ideal PhD project; (c) it would give me opportunities to develop skills such as writing, leadership, networking, coordinating maddening clinical trials…
At the start of my studentship I got a bit philosophical and read a little bit on the history of the PhD. My information comes from Wikipedia and the University of Melbourne PhD handbook. According to Wikipedia, the term doctor probably originally referred to apostles or Christian authorities who taught the bible, a doctorate being thought of as a “licence to teach”. The Doctor of Philosophy was created by a Philosophy department in a German University and was adopted in the USA in the 19th century.
There’s a detailed definition of what a PhD is defined as in our official PhD handbook but the overall idea is that “The degree of Doctor of Philosophy signifies that the holder has undertaken a substantial piece of original research which has been conducted and reported by the holder under proper academic supervision and in a research environment for a prescribed period”. In other words, this poor sod actually stuck it through the entire process of designing and implementing a research project, and lived to tell the tale (in 80-100,000 words excluding references and tables). And, I like this, “It is a careful, rigorous and sustained piece of work demonstrating that a research “apprenticeship” is complete and the holder is admitted to the community of scholars in the discipline.”
I have visions of a “community of scholars” wearing puffy hats and cravats and drinking claret and hobnobbing in the evenings.
Unfortunately the advice of others to do it as “you just have to write a thesis at the end” was not quite the best reason to pursue a PhD. I am doing it perhaps BECAUSE I have to write a thesis, and hopefully not at the end either. I have always wanted to be a writer and by the end of it all if I am not a writer I don’t know when I’ll ever be one.