Last I knew, Dr. Frankenstein of popular knowledge was a fictional character (I could be wrong), but it's also possible that somebody somewhere surnamed Frankenstein also earned a doctorate in something. Such as "Truth in Jernalism."
When I read the novel, some years ago but later in life, I couldn't escape the impression that the voice of Victor Frankenstein was the voice of Mary Shelley herself. The whole thing was just insanely Freudian. Don't get me going. So, fiction yeah, but it does have a grip on us.