Hume: Necessity Is Not a Force in Things

The Quote

"It is universally allowed, that matter, in all its operations, is actuated by a necessary force" is Hume's statement of the received view of natural necessity in Section VIII of An Enquiry Concerning Human Understanding. The sentence matters less for its content than for what Hume does with it: he takes the determinist's premise and shows that, analyzed correctly, it undermines the very picture of compelled causation that makes determinism seem threatening.

Context

The passage occurs at the start of the second part of "Of Liberty and Necessity." In the first part Hume argued that human actions are as regular as natural events; now he addresses the objection that natural events are necessary in a way human actions are not. His reply is that the necessity of nature is not what common sense takes it to be: it is not an observed force or energy inhering in causes, but a projection of the mind's habit of expectation onto the constant conjunction of like objects.

Meaning & Interpretation

The irony of the passage is that it grants the strong determinist thesis — "no other effect, in such particular circumstances, could possibly have resulted" — and then defuses it. Since "necessity" names no discovered quality in things but a regularity of experience plus a custom of inference, the claim that human actions are necessary is not a claim that they are compelled; it is a claim that they are regular and predictable. And regularity is not the enemy of freedom. The compatibilist conclusion follows: praise, blame, and responsibility are consistent with the uniformity of human behavior, because responsibility tracks the agent's will and character, not the absence of causes.

Legacy

Hume's analysis of necessity is one of the founding moves of the philosophy of science. It informed the regularity theory of laws, the logical empiricist account of causation, and the modern debate over the metaphysics of causal necessity — whether laws are merely regularities or express genuine modal force. In the free will debate, Hume's deflationary necessity remains the classic compatibilist strategy: define the threatening term down to something harmless, and the conflict with freedom dissolves.

Sources

1. Morris, W. E. & Brown, C. R. (2020). "David Hume." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/hume/
2. Hume, D. (1748). An Enquiry Concerning Human Understanding, Section VIII. Project Gutenberg.
3. Henderson, L. (2020). "The Problem of Induction." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/induction-problem/
4. Hoefer, C. (2016). "Causal Determinism." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/determinism-causal/