The most famous opinion from Jacobellis, however, was Justice Potter Stewart's concurrence, holding that the Constitution protected all obscenity except "hard-core pornography." Stewart wrote, "I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description; and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that." (emphasis added