sufficient cause to explain the effect. For the argument must be that
the system of the material world demands as a cause a corresponding
system of interconnected ideas; but such a mental system would demand an
explanation of its existence just as much as the material world; and
thus we find ourselves

[162] committed to an endless series of causes. But in any case, even if
the argument held, it would prove only the existence of a Deity whose
powers, though superior to man’s, might be very limited and whose
workmanship might be very imperfect. For this world may be very faulty,
compared to a superior standard. It may be the first rude experiment “of
some infant Deity who afterwards abandoned it, ashamed of his lame
performance”; or the work of some inferior Deity at which his superior
would scoff; or the production of some old superannuated Deity which
since his death has pursued an adventurous career from the first impulse
which he gave it. An argument which leaves such deities in the running
is worse than useless for the purposes of Deism or of Christianity.

The sceptical philosophy of Hume had less influence on the general
public than Gibbon’s Decline and Fall of the Roman Empire. Of the
numerous freethinking books that appeared in England in the eighteenth
century, this is the only one which is still a widely read classic. In
what a lady friend of Dr. Johnson called “the two offensive chapters”
(XV and XVI) the causes of the rise and success of Christianity are for
the first time critically investigated as a simple historical
phenomenon. Like most freethinkers of the

[163] time Gibbon thought it well to protect himself and his work
against the possibility of prosecution by paying ironical lip-homage to
the orthodox creed. But even if there had been no such danger, he could