A typical package-deal, used by professors of philosophy, runs as follows: to
prove the assertion that there is no such thing as “necessity” in the universe,
a professor declares that just as this country did not have to have fifty
states, there could have been forty-eight or fifty-two—so the solar system did
not have to have nine planets, there could have been seven or eleven. It is
not sufficient, he declares, to prove that something is, one must also prove
that it had to be—and since nothing had to be, nothing is certain and
anything goes.