Hume’s ‘refutation’ of induction essentially goes as follows:
- There are only three possible kinds of knowledge: (a) ‘relations of ideas,’ which are things that are true by definition, (b) direct observations, and © knowledge based on inductive reasoning, where an inductive inference is a generalization from experience.
- Any generalization from experience presupposes ‘the Uniformity Principle’ – i.e., that the course of nature is uniform, or that the future will resemble the past.
- So inductive knowledge can only be justified if this presupposition is justified.
- The Uniformity Principle is not true by definition.
- Nor is its truth is direcly perceived.
- And since all inductive inference presupposes the Uniformity Principle, any inductive argument for it would be circular.
- So the Uniformity principle cannot be justified. (from 1,4,5,6)
- Hence, no inductive conclusion is justified.