Hume, D. (2006). An Inquiry Concerning Human Understanding, Section IV, Part II. Urbana, Illinois: Project Gutenberg. (Original work published in 1748)
inductive-inferences (reasoning from observed to unobserved cases) is the basis of both predictive beliefs and general laws. Hume asks,
the problem of induction = what rational basis do we have for believing that the causal relations we’ve experienced in the past will persist into the future?
“As to past Experience, it can be allowed to give direct and certain information of those precise objects only, and that precise period of time, which fell under its cognizance: but why this experience should be extended to future times, and to other objects, which for aught we know, may be only in appearance similar; this is the main question on which I would insist.”
This cannot be justified deductively (it isn’t a logical truth), and as Hume shows, it cannot be justified inductively either.
Induction is grounded in causal reasoning
Hume argues that our inductive reasoning is grounded in our idea of Causality. When we see one event regularly followed by another, we form the belief that the first caused the second and use that to made predictions. The basis for all cauasal inferences and predictions about the world, for Hume, is past experience.
In Humean-theory-of-causation, the metaphysical claim that necessary-connection between cause and effect is not real but psychological leads directly to this epistemological conclusion: our confidence in induction is not rationally justified, but rather a product of habit formed by repeated experiences of conjoined events.
Principle of the uniformity of nature
Hume notes that in making an inference from observed cases to unobserved cases, there seems to be a missing premise called the
principle of the uniformity of nature1 = premise that nature is uniform in the sense that regularities that have occurred in the past will persist in the future, or as Hume puts it, “the future will be conformable to the past”.
This makes an inductive argument into a deductive one.
- Object of type X have always been observed to be accompanied by effects of type Y
- principle of the uniformity of nature = the future will be conformable to the past
- Conclusion: Therefore, in the future, any object of type X will be accompanied by effects of type Y
The principle of the uniformity of nature acts as bridge between the observed cases to the unobserved.
Why believe in the principle?
Hume notes:
- the principle is not a tautology (necessary truth)
- it is not an a priori
Hume concludes that the principle, if justified at all, would have to be justified based on past experience. And would need an argument like:
- In the past, some regularities have been observed as persisting over some stretch of time
- Conclusion: Therefore, past regularities will persist into the future
But this is also an inductive argument. Giving us a circular argument; to justify induction, we invoke the principle of uniformity of nature; to justify uniformity of nature, we invoke induction. This makes the whole approach viciously circular / it seems to “beg the question”
i.e. that the attempt to justify inductive inference already relies on inductive inference
causal powers as evidence
from the regular connection that we’ve observed between fire and smoke, can we not infer that fire has a causal power to produce smoke, generally?
Even if we infer that objects have causal powers from past experience, our belief that those powers will continue to operate in the same way in the future already presupposes what we’re trying to prove — that the future will resemble the past.
Hume’s positive view of Induction
Hume critiques that inductive inferences are not rationally justified, but he believes that we do and we have to make inductive inferences.
“None but a fool or a mad man will ever pretend to dispute the authority of experience, or to reject that great guide to human life.” - Hume, an inquiry concerning human understanding
“… But still he finds himself determined to draw [this inference] … There is some other principle which determines him to form such a conclusion. This principle is custom or habit.” - Section V, Part I, An enquiry concerning human understanding
For Hume, like his idea of necessary-connection, our inclination to make inductive inferences is due to the habit bred in us by repeated experiences of past regularities.
For Hume, inductive inferences provide no rational basis for beliefs beyond experience, even though we’re psychologically determined to form those beliefs on the basis of evidence that we have.
Other ideas on the problem of induction
Popper on the problem of induction =
Whether inductive inferences can be justified is called the problem-of-induction, but can also be described as “the question of the truth of universal statements which are based on experience”, such as hypotheses and theoretical claims in science.
Link to original
Circular transclusion detected: Philosophy/popper-1934-logic-of-scientific-discovery
Foster-proposed-solution-to-the-problem-of-induction noted that observed regularities are evidence of natural necessity, and the inference to laws embodying natural necessity justifies conclusions that past regularities will persist in the future.
Footnotes
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Hume does not use this name particularly, but this name is used in literature of induction ↩