Final answer:
The 18th-century treatise The System of Nature, which introduces an atheist philosophy, was penned by Baron d'Holbach, representing a substantial deviation from the typically more religious or deist perspectives of the Enlightenment era philosophers.
Step-by-step explanation:
The 18th-century treatise The System of Nature, which expounds an atheist philosophy, was written by Baron d'Holbach. The 18th-century treatise The System of Nature, which introduces an atheist philosophy, was penned by Baron d'Holbach, representing a substantial deviation from the typically more religious or deist perspectives of the Enlightenment era philosophers.
This work presented a radically different perspective compared to other Enlightenment philosophers like John Locke, who was religious and wrote arguments for God's existence, and David Hume, who was more of a skeptic towards organized religion but not outright atheist. The treatise significantly contributed to the philosophical and scientific activity of the time, challenging traditional doctrines and playing a part in the critical exploration during the Enlightenment.