# Section I: Of Liberty and Necessity explained — A Treatise of Human Nature

> Chapter companion for A Treatise of Human Nature by David Hume.

## What happens

Hume examines the will and the long-disputed question of liberty and necessity. He argues that the operations of the mind are as necessary as those of matter, since both are based on constant union and the inference of the mind. He contends that moral evidence, derived from the constant conjunction of motives and actions, is as reliable as physical evidence, and that liberty, if it removes necessity, is equivalent to chance and contradicts experience.

## Themes in this chapter

### Empiricism and the Primacy of Impressions

Hume grounds the idea of necessity in the constant union of objects and the inference of the mind, both derived from experience and impression.

### Custom and General Rules

The inference from constant union is a product of custom and habit, which shapes our expectations and judgments about both natural and moral events.

### Skepticism About the External World

Hume emphasizes that we cannot penetrate the essence of bodies to discover necessary connections; we only observe constant conjunction, leading to a skeptical view of causal necessity.

## Character check-ins

### David Hume

Hume presents his argument on liberty and necessity, defining the will and asserting that human actions are as necessary as natural events.

### Julius Caesar

Mentioned as an example of historical facts inferred from moral evidence, such as the death of Caesar.

## Key lines

> By the will, I mean nothing but the internal impression we feel and are conscious of, when we knowingly give rise to any new motion of our body, or new perception of our mind.

The will is the internal impression we are conscious of when we intentionally initiate a bodily movement or a mental perception.

_Hume defines the will as an impression, aligning with his empiricist framework._

> It is their constant union alone, with which we are acquainted; and it is from the constant union the necessity arises.

We only know the constant conjunction of objects, and it is from this constant conjunction that our idea of necessity arises.

_Hume reduces necessity to constant union and mental inference, rejecting any insight into essential connections._

> The same prisoner, when conducted to the scaffold, foresees his death as certainly from the constancy and fidelity of his guards as from the operation of the ax or wheel.

A prisoner on the way to execution predicts his death with equal certainty from the reliability of his guards as from the physical operation of the executioner's tools.

_This illustrates that moral evidence (human behavior) is as reliable as physical evidence._

> According to my definitions, necessity makes an essential part of causation; and consequently liberty, by removing necessity, removes also causes, and is the very same thing with chance.

In my definitions, necessity is essential to causation; therefore, liberty, by removing necessity, also removes causes and becomes identical to chance.

_Hume argues that liberty, if it negates necessity, is equivalent to chance and thus contradictory._

## Links

- HTML: https://www.betterreads.online/discover/a_treatise_of_human_nature_se/chapters/section-i-of-liberty-and-necessity
- Book: https://www.betterreads.online/discover/a_treatise_of_human_nature_se
- All chapters: https://www.betterreads.online/discover/a_treatise_of_human_nature_se/chapters