The Illusion of Free Will
Holbach begins this excerpt by reciting a large number of circumstances over which humans have no control. People have no control over the circumstances of their birth and their physiology, they form habits due to the unnoticed influence of others, and they are perpetually affected by natural phenomena that change their behavior. In light of the amount of human behavior caused by external influences, Holbach finds it surprising that people still believe that they have free will. Instead, he argues that the brain – like any other organ – simply responds to impulses, and that its actions necessarily follow from the impulses it receives. "[H]e always acts according to necessary laws from which he has no means of emancipating himself."
To illustrate his claim, Holbach describes circumstances in which humans appear to exercise free will and argues that even those are best explained by positing that human action is wholly determined by natural laws. A person with a virulent thirst, for example, may appear unable to resist the urge to drink from a fountain. However, if he learned that the fountain was poisoned and declined to drink, one might argue that he freely chose not to drink. Holbach thinks that that view is mistaken, though, for the person is disposed by natural laws to not drink water he knows is poisoned in the same way that the thirsty person is disposed by natural laws to drink water he knows is clean. The reason some people believe that human behavior is not determined, Holbach argues, is that the causes underlying human behavior are complex. We cannot perceive all of the complex and interrelated causes of human behavior, and therefore do not believe that human behavior is necessarily determined by natural law. If, however, we could perceive all of the complex causal relations, Holbach argues that we would be convinced that humans do not have free will: "if his machine were less complicated, he would perceive that all his actions were necessary."