THE STORY OF PHILOSOPHY2 The Lives and Opinions

i 7 6 THE STORY OF PHILOSOPHY
Though La Mettie was exiled for these opinions, Helvetius (1715-71),
who took them as the basis of his book On Man, became one of the rich-
est men in France, and rose to position and honor. Here we have the
ethic, as in La Mettrie the rnetaphysic. of atheism. All action is dictated
by egoism, self-love; "even the hero follows the feeling which for him is
associated with the greatest pleasure"; and "virtue is egoism furnished
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with a spy-glass. Conscience is not the voice of God, but the fear of the
police; it' is" the deposit left in us from the stream of prohibitions poured
over the growing soul by parents and teachers and press. Morality must
be founded not on theology but on sociology; the changing needs of
society, and not any unchanging revelation or dogma, must determine
the good.
The greatest figure in this group was Denis Diderot (1713-84). His
ideas were expressed in various fragments from his own pen, and in the
System of Nature of Baron d'Holbach (1723-89), whose salon was the
centre of Diderot's circle. "If we go back to the beginning," says Holbach,
"we shall find that ignorance and fear created the gods; that fancy, enthusiasm
or deceit adorned or disfigured them; that weakness worships
them; that credulity preserves them; and that custom respects and tyranny
supports them in order to make the blindness of men serve its own interests."
Belief in God. said Diderot, is bound up with submission to
autocracy; the two rise and fall together: and "men will never be free
till the last king is strangled with the entrails of the last priest." The
earth will come into its own only when heaven is destroyed. Materialism
may be an over-simplification of the world all matter is probably instinct
with life, and it is impossible to reduce the unity of consciousness to
matter and motion; but materialism is a good weapon against the Church,,
and must be used till a better one is found. Meanwhile one must spread
knowledge and encourage industry; industry will make for peace, and
knowledge will make a new and natural morality.
These are the ideas which Diderot and d'Alembert labored to dis-
seminate through the great Encyclopedia which they issued, volume by
volume, from 1752 to 1772. The Church had the first volumes suppressed;
and, as the opposition increased, Diderot's comrades abandoned him; but
he worked on angrily, invigorated by his rage. "I know nothing so in-
decent," he said, "as these vague declamations of the theologians against
reason. To hear them one would suppose that men could not enter im>
the bosom of Christianity except as a herd of cattle enters a stable." It
was. as Paine put it, the age of reason; these men never doubted that the
intellect was the ultimate human test of all truth and all good. Let reason
be freed, they said, and it would in a few generations build Utopia.
Diderot did not suspect that the erotic and neurotic Jean Jacques Rous-
seau (1712-78), whom he had just introduced to Paris, was carrying iu
Taine, The Ancient Rtsim*.