The System of Nature, 1770, which bore on its title page the name of Mirabaud, who had died 1760, proceeded from the company of freethinkers accustomed to meet in the hospitable house of Baron von Holbach (died 1789), a native of the Palatinate. Its real author was Holbach himself, although his friends Diderot, Naigeon, Lagrange, the mathematician, and the clever Grimm (died 1807) seem to have co-operated in the preparation of certain sections. The cumbrous seriousness and the dry tone of this systematic combination of the radical ideas which the century had produced, were no doubt the chief causes of its unsympathetic reception by the public. Similarly unsuccessful was the popular account of materialism with which Holbach followed it, in 1772, and Helvetius’s excerpts from the System of Nature, 1774.
Holbach applies himself to the despiritualization of nature and the destruction of religious prejudices with sincere faith in the sacred mission of unbelief—the happiness of humanity depends on atheism. “O Nature, sovereign of all beings, and ye her daughters, Virtue, Reason, and Truth, be forever our only divinities.” What has made virtue so difficult and so rare? Religion, which divides men instead of uniting them. What has so long delayed the illumination of the reason, and the discovery of truth? Religion with its mischievous errors, God, spirit, freedom, immortality. Immortality exists only in the memory of later generations; man is the creature of a day; nothing is permanent but the great whole of nature and the eternal law of universal change. Can a clock broken into a thousand pieces continue to mark the hours? The senseless doctrine of freedom was invented only to solve the senseless problem of the justification of God in view of the existence of evil. Man is at every moment of his life a passive instrument in the hands of necessity; the universe is an immeasurable and uninterrupted chain of actions and reactions, an eternal round of interchanging motions, ruled by laws, a change in which would at once alter the nature of all things. The most fatal error is the idea of human and divine spirits, which has been advanced by philosophers and adopted with applause by fools. The opinion that man is divided into two substances is based on the fact that, of the changes in our body, we directly perceive only the external molar movements, while, on the other hand, the inner motions of the invisible molecules are known only by their effects. These latter have been ascribed to the mind, which, moreover, we have adorned with properties whose emptiness is manifested by the fact that they are all mere negations of that which we know. Experience reveals to us only the extended, the corporeal, the divisible—but the mind is to be the opposite of all three, yet at the same time to possess the power (how, no man can tell) of acting on that which is material and of being acted upon by it. In thus dividing himself into