I wrote the following sentence and was criticized for using a comma before the quotation marks.
Steve states: The topic for discussion will be Friedrich Nietzsche's controversial philosophical concept of the, "Superman or Overman."
The "Ubermensch" was Nietzsche's concept but the English translations of it, that Steve insisted I use because other people use them, were not his and more importantly they are both incorrect. The correct translation would be, "Superhuman," as the concept was not meant to be gender specific.
Is using a comma before quotation marks in the above sentence, for the reasons that I have stated, acceptable or not?