A product of the French Enlightenment, mechanism (or materialism) was a philosophy that centered around the idea that man was simply a machine, incapable of being held morally accountable for his actions. The materialists believed that there was no spiritual aspect to the human body, and that morality was totally unnatural. La Mettrie, an important materialist thinker, wrote a book titled The Human Machine that said the greatest virtue is self love, and that the pursuit of pleasure the greatest occupation. Helvetius, another French materialist, attempted to create laws of humanity that governed what humans do and why they do it. He also believed that people have no free choice between right or wrong. Called the personal enemy of the Almighty, Baron d’Holbach thought that crime and moral degeneracy were just mental imbalances, and not manifestations of good or evil. These ideas were directly influenced by the period of the Enlightenment, and most especially the French Enlightenment.