According to dHolbach, nature is a great chain of causes and effects. Nature is the great whole, comprising everything visible and invisible. Baron d Holbach gives the laws of the physical world based on laws of motion and gravitation, as given by Newton, and he wants to apply the law of attraction and repulsion in the field of morality. All knowledge comes through the sense organs created by the impressions of the world and deposited in the brain, which is the real seat of thought. Man searches for happiness in this world, but the priesthood misguides the people by asking them to look for happiness in future life, as guided by the chimeras of religion. Man living in society should be guided by reason, experience, and sciences by working for his happiness and contributing to the happiness of other members of the society by his hard work, talent, and virtues, by being useful to others by satisfying their needs while satisfying his own needs. Happiness is on this earth, and by reason and experience, he can be happy, and not as the priesthood preaches in another future life.

Originally published in 1984. Paul Henri Thiery, Baron d'Holbach (1723-1789), was the center of the radical wing of the philosophers. Holbach wrote, translated, edited, and issued a stream of books and pamphlets, often under other names, that has made him the despair of bibliographers but has connected his name, by innuendo, gossip, and association, with most of what was written in defeense of atheistic materialism in late eighteenth-century France. Holbach is best known for The System of Nature (1770) and deservedly, since it is a clear exposition of his main ideas. His initial position determines all the rest of his argument: 'There is not, there can be nothing out of that Nature which includes all beings.' Conceiving of nature as strictly limited to matter and motion, both of which have always existed, he flatly denies that there is any such thing as spirit or supernatural. This is the first of three volumes.

Paul-Henri Thiry, Baron d'Holbach, was a French-German author, philosopher, encyclopedist and prominent figure in the French Enlightenment.