14. In 1773 Holbach published his _Recherches sur les Miracles_,
a much more sober work than his previous writings on religion. In
this book he raises the well known difficulties with belief in
miracles and brings a great deal of real learning and logic to
bear on the question. The entire work is in a reasonable and
philosophic spirit. His conclusion is that "une vraie religion
doit avoir au defaut de bonnes raisons, des preuves sensibles,
capables de faire impression sur tout ceux qui la cherchent de
bonne foi. Ce ne sont pas les miracles." The same year he
published two serious but somewhat tiresome works on politics.

15. _La politique naturelle_.

16. _Systeme social_ in which he attempts to reduce government
to the naturalistic principles which were the basis of his entire
philosophy. The first is also attributed to Malesherbes. There
is a long and keen criticism of the _Systeme Social_ by
Mme. d'Epinay in a letter to Abbe Galiani Jan. 12, 1773
(Gal. _Corresp._, Vol. II, p. 167).

But the most interesting reaction upon it was that of the Abbe
Richard who criticized it from point of view of the divine right
of kings in his long and tiresome work entitled _La Defense de
la religion, de la morale, de la vertu, de la politique et de
la societe, dans la refutation des ouvrages qui ont pour titre,
l'un Systeme Social etc. Vautre La Politique Naturelle par le
R. P. Ch. L. Richard, Professeur de Theologie_, etc., Paris,
Moulard, 1775.