I spent a lot of time in Google Books. I also use other quote
  investigators but then investigate their conclusions to see if
  they match to my satisfaction. I even had to subject one of my
  favorites to it: Carl Sagan and his Star Stuff. I wanted to see
  if it was his and really "From Ancient Times People Believed". I
  wanted to believe that, and did because, well he's Carl. But
  alas, I tracked it down as far as I could go, and it wasn't his.
  I drew up this cruddy graphic to show the results of my
  investigation. I was disappointed in Carl Sagan but then I had
  to remind myself that he was a Science promoter and motivational
  speaker, and complete accuracy wasn't really critical for his
  teaching methods. Yeah, he lied. But I'm ok with that. Most of
  what he talked about was fantastic and really, he's human and
  had a job to do and did it very very well. He was waxing poetic
  and I can forgive that but I like finding out when concepts
  originated. It's not easy to figure out when concepts originated
  within history. Words change with the times, Hard to find exact
  quotes when you get beyond a certain point and so you have to
  settle sometimes. There's mythological components to nearly
  every area of human inquiry, including within the sciences, and
  I like piecing apart where the traceable stuff is, and where the
  mythology is. You can count that if you like. I'm going for
  historical continuity that leads to today. If there's broken
  lines, then I leave it behind with their originators. Another
  example: Gnosticism. For me, gnosticism died out when the
  gnostic movements broke up in the 2nd 3rd centures ad. Later on,
  other groups considered themselves gnostic. But they weren't
  gnostic to me, even if they picked up original texts and
  attempted to start over from them. It's not the same. Culture is
  gone and buried and dead and any recreation belongs with the
  generation that did the reenactment, not with the originals.
  Yes, I believe he did that as well. String of pearls threaded
  through history... .although there's no traceable threads
  inbetween. That's why I consider them separate occurrences of
  similar ideas. It's likely he read it somewhere and was inspired
  and then forgot where it came from. Happens to me all of the
  time; a trait I'm trying to get rid of but it's not easy smile
  emoticon We view history differently that's all. I see pockets
  of civilizations and then look for the threads that connect
  them, and then the threads that don't connect with continuity.
  I'm not suggesting that everybody else think like me Not at all.
  Evidence is in this thread. You see history one way, I see
  history another. Do you suggest there is a singular manner in
  which to approach history?   I'm not saying they didn't.
  I'm saying there's no historical continuity I can find that
  links culture-to-culture with that belief.   yes, I'm aware. I
  study mythologies and tracing concepts within cultures.

  We are in a culture right now. We have our own mythologies.

  100 years from now, dominant cultures will have THEIR
  mythologies. Some will link up to today. Perhaps someone will
  find an ancient unknown text and start talking about it as if
  people "always believed it" when we currently don't even know
  about it.

  You're not wrong. The Historical Methodology is not wrong.

  I'm working at it from a different angle that's all. I'm sorry
  if you don't like it.   It's bad form to presume your
  conversation partner is dumb. I don't believe I assumed you
  were. If I did, I apologize. I trace concepts within cultures.
  It requires a slightly different tactic.