I am thinking of doing an EdD and in preparation have taken part in a couple of MOOCs for research methods. They delved deeply into the history of science, beginning with ancient philosophy. While interesting, it was a lot to digest and it left me wondering how broad my knowledge would have to be for doctoral studies. I could see the point of giving some background to how research has come to be, and also insights to the different research methods and approaches, but I wonder how much I would be expected to 'know' or carry round in my head so the information is on-demand.
Does this query make sense? If I do doctoral studies, should I expect to also know a lot about philosophy, politics, history etc (as the content of these courses suggest)?