ecision,
with which Descartes grasped the problem of vital dynamics constitute
a marvellous illustration of intellectual power. [Footnote: See
Huxley's admirable 'Essay on Descartes.' Lay Sermons.]

During the Middle Ages the doctrine of atoms had to all appearance
vanished from discussion. It probably held its ground among
sober-minded and thoughtful men, though neither the church nor the
world was prepared to hear of it with tolerance. Once, in the year
1348, it received distinct expression. But retractation by compulsion
immediately followed; and, thus discouraged, it slumbered till the
seventeenth century, when it was revived by a contemporary and friend
of Hobbes of Malmesbury, the orthodox Catholic provost of Digne,
Gassendi. But, before stating his relation to the Epicurean doctrine,
it will be well to say a few words on the effect, as regards science,
of the general introduction of monotheism among European nations.

'Were men,' says Hume, 'led into the apprehension of invisible
intelligent power by contemplation of the works of Nature, they could
never possibly entertain any conception but of one single Being, who
bestowed existence and order on this vast machine, and adjusted all
its parts to one regular system.' Referring to the condition of the
heathen, who sees a god behind every natural event, thus peopling the
world with thousands of beings whose caprices are incalculable, Lange
shows the impossibility of any compromise between such notions and
those of science, which proceeds on the assumption of never-changing
law and causality. 'But,' he continues, with characteristic
penetration, 'when the great thought of one God, acting as a unit upon
the universe, has been seized, the connection of things in accordance
with the law of cause and effect is not only thinkable, but it is a
necessary consequence of the assumption. For when I see ten thousand
wheels in motion, and know, or believe, that they are all driven by
one motive power, then I know that I have before me a mechanism, the
action of every part of which is determined by the plan of the whole.
So much being assumed, it follows that I may investigate the structure
of that machine, and the various motions of its parts. For the time
being, therefore, this conception renders scientific action free.' In
other words, were a capricious God at the circumference of every wheel
and at the end of every lever, the action of the machine would be
incalculab