a philosophic principle. Shaftesbury
had indirectly drawn it from Locke, and through Hutcheson it became the
source and sponsor of the Scottish philosophy of that century. This was
a weapon exactly adapted for dealing with a theology that was
discredited in the eyes of all cool observers by the hysterical
extravagances of one set of religionists, and the factious pretensions
of their rivals. And no other weapon was at hand. The historic or
critical method of investigation was impossible, for the age did not
possess the requisite learning. The indirect attack from the side of
physical science was equally impossible. The bearing of Newton's great
discovery on the current conceptions of the Creator and the supposed
system of the divine government, was not yet fully realised. The other
scientific ideas which have since made the old hypothesis less credible,
were not at that time even conceived.

Diderot did indeed perceive even so early as this that the controversy
was passing from the metaphysicians to the physicists. Though he for the
moment misinterpreted the ultimate direction of the effect of
experimental discovery, he discerned its potency in the field of
theological discussion. "It is not from the hands of the metaphysician,"
he said, "that atheism has received the weightiest strokes. The sublime
meditations of Malebranche and Descartes were less calculated to shake
materialism than a single observation of Malpighi's. If this dangerous
hypothesis is tottering in our days, it is to experimental physics that
such a result is due. It is only in the works of Newton, of
Muschenbroek, of Hartzoeker, and of Nieuwentit, that people have found
satisfactory proofs of the existence of a being of sovereign
intelligence. Thanks to the works of these great men, the world is no
longer a god; it is a machine with its cords, its pulleys, its springs,
its weights."[32] In other words, Diderot had as yet not made his way
beyond the halting-place which has been the favourite goal of English
physicists from Newton down to Faraday.[33] Consistent materialism had
not yet established itself in his mind. Meanwhile he laid about him with
his common sense, just as Voltaire did, though Diderot has more
weightiness of manner. If his use of the weapon cannot be regarded as a
decisive settlement of the true issues, we have to remember that he
himself became aware in a very short time of its inadequateness, and
proceeded to the discussion, as we sh