In 1955, the noted gemmologist and
contrarian Sir Nelson Goodman, in a brief note published in the proceedings of
the Devonshire Horticultural Society, questioned the received wisdom concerning
the colour of emeralds. “Everyone
says that they are by nature green,”
he noted, “simply because they have always been
green.” (Note that, in Sir Nelson’s
quaint dialect, “been” and “green” actually rhyme.) “But our observations to that effect, however numerous and
of however long standing, may equally be marshaled to support the thesis that
they are in fact grue: which is to say, green prior to 18
November 2018, and blue thereafter.”
In the half century or more that
has elapsed since that time, all sorts of philosophical fuss about “projectible
predicates” and whatnot (green but
not grue enjoying this rather circular distinction), but in all of
that, thinkers lost sight of the basic facts of the matter: are emeralds in
fact green, or grue, or what?
We need wonder no longer, for the
great day -- 18 November 2018 -- has arrived at last.
And it turns out that last night, all over the planet, and
into the deepest recesses of intersteller space, quite at the stroke of
midnight, every last emerald did
in fact turn blue. Or rather, “grue”.
So now we know.
