Summary: An Enquiry Concerning Human Understanding, By David Hume

In the work of David Hume, he argues that human knowledge about the external world are driven from sense experience. Our sense gives us knowledge about objects we can observe, and our memory can give us knowledge about objects that we have observed. Thus, people often assume that we have knowledge about things that are not currently present to our sense because objects and events are bound together as causes and effect, namely causation. As a result, once we know a cause, then we could infer its effect, vice versa. However, in his book An Enquiry Concerning Human Understanding, he criticized the notion of cause and effect by claiming causation is a custom or habit of association, a belief that is based on causation is meaningless. In this paper,

Then, we won’t have liberty. Because we will always be able to know what will happen in the future. In another word, we will be always living in the past, since there is no difference between future and the past. However, Hume argues that liberty and necessity can happily coexist. because all human has the same faculty, the power of the mind. While we recognize that we habitually make a certain inference that cannot be justified, but we can still believe in both liberty and necessity, because conforming to our common sense. We tend to act as if human action is determined, while also believing in freedom to choose. Hume’s theory of causation from constant conjunction not only applies to physical things, but also to the motivations and actions of human will. Like many things in the natural world, humans actions are largely predictable and has a reason that is based on our custom, but that reason (as we think as“cause”) can be will. Constant conjunction is the unspoken rule, it doesn't justify the action follow by the “cause”, but it explains why we make voluntary actions. Therefore, there is necessity and