Thornton seemed to have the insight that there are more interesting things than "painting," and that these things are (or can be assimilated with) painting, that painting is not the historical given. There is no "natural" painting but merely an inherited set of tropes that no one said you even have to play by. Rules to a game you didn't even realize existed. Kin say Richard Aldrich where almonds or pennies might be an equal painting axiom as Greenbergian "flatness". Inflate a mattress, call it painting, it's not revolutionary except for the fact that no one else is on the same gameboard.
A "befuddlement of the terms and conditions of paintings... obtuse, tangential starts digressing from those painting histories generally acceptable as beginnings. If the paintings seem facetious or frivolous it is because [x] doesn't necessarily [deem sacrosanct] the histories that are painting cannon..." Need not reinscribe them to reflect in them.
See too: Richard Aldrich at Gladstone Gallery, Darren Bader at Andrew Kreps