objection had been more pithily expressed by Pascal long before, in the
famous article of his Thoughts, on the difficulty of demonstrating the
existence of a deity by light of nature.[50] Diderot's argument does not
extend to dogmatic denial. It only shows that the deist is exposed to an
attack from the same sceptical armoury from which he had drawn his own
weapons for attacking revelation. It is impossible to tell how far
Diderot went at this moment. The trenchancy with which his atheist urges
his reasoning, proves that the writer was fully alive to its force. On
the other hand, the atheist is left in the midst of a catastrophe. On
his return home, he finds his children murdered, his house pillaged, and
his wife carried off. And we are told that he could not complain on his
own principles.

If the absence of witnesses allowed the robber to commit his crime with
impunity, why should he not? Again, there is a passage in which the
writer seems to be speaking his own opinions. An interlocutor maintains
the importance of keeping the people in bondage to certain prejudices.
"What prejudices? If a man once admits the existence of a God, the
reality of moral good and evil, the immortality of the soul, future
rewards and punishments, what need has he of prejudices? Supposing him
initiated in all the mysteries of transubstantiation, consubstantiation,
the Trinity, hypostatical union, predestination, incarnation, and the
rest, will he be any the better citizen?"[51]

In truth, Diderot's mind was at this time floating in an atmosphere of
rationalistic negation, and the moral of his piece, as he hints, points
first to the extravagance of Catholicism, next to the vanity of the
pleasures of the world, and lastly, to the unfathomable uncertainty of
philosophy. Still, we may discern a significant leaning towards the
theory of the eternity of matter, which has arranged itself and assumed