That purveyor of pessimistic empiricism, John Locke, wrote in 1690 "First, Essence may be taken for the very being of anything, whereby it is what it is." (link and check out the verse in that footnote). I am just a little bit heartened by the image of a football linesman reading An Essay of Human Understanding in the locker room (NPI). Although, on second thought, they probably default to Heidegger on Being and Wittgenstein on language games.

Ceci n'est pas un seing.