In the comments on my post "When did 'a thing' become a thing", 4/18/2016,, James Barrett points us to a video from the Royal Society that includes the following passage from a letter, dated 1783, from one Eberhard Johann Schröter in St. Petersburg, addressed to Dr. Daniel Solander, an associate of Sir Joseph Banks:
If any body could be thoroughly convinced that a prediction of winds is a thing and possible and real, then to such a person a proper classification of them would be useful.
(This letter was selected to be read because its card was the very last item in the card catalogue of the Royal Society's library.)
This citation suggests that the "is a thing" usage has always been Out There in platonic Idiom World, and may have been incarnated many times through history before it finally caught the memetic brass ring. And never mind that Eberhard Schröter was presumably not a native speaker of English.