From a sermon I heard at camp this summer...
"Ouija" = "oui" ('yes' in French) + "ja" ('yes' in German), making the "ouija board" a "yes-yes board"
Therefore, Satan is the originator of Positive Thinking.
This was in a sermon from Nehemiah 6 titled "Say No to Ono."
Fortunately, this was not typical of the preaching at camp, or I would have drowned myself in the lake long before my 11-week contract was up!