Hume’s Argument that Inductive Reasoning in Science Cannot Be
Rationally Justified (restated)
1. All inferences from experience to conclusions about the future
presuppose the principle that the future will resemble the past.
(Principle of the Uniformity of Nature)
a. If we suspect that the course of nature may change and that
the past is no guide to the future, then all experience becomes
useless and does not support any conclusion about the future.
2. Therefore, no argument from experience can support the
principle that the future will resemble the past.
3. No deductive argument can establish the principle that the
future will resemble the past.
4. Therefore, the Principle of the Uniformity of Nature cannot be
rationally justified.
5. If the Principle of the Uniformity of Nature cannot be rationally
justified, then inductive reasoning in science cannot be
rationally justified.
6. Therefore, inductive reasoning in science cannot be rationally
justified.
 To solve a problem is to answer correctly the question(s) that it
poses.
 To dissolve a problem is to show that it is not really a
problem—i.e., does not pose any significant questions.
The problem of induction poses the question: How should we
respond to Hume’s argument?
Possible Responses to Hume’s Argument:
1. Premise 5 is false: inductive reasoning is inherently rational.
2. Hume argument implies that inductive reasoning can be
justified only on the basis of deductive reasoning.
3. Premise 3 is false: the Principle of the Uniformity of Nature can
be derived from the mathematical theory of probability.
4. The inference from premises 2 and 3 to 4 is invalid: we have a
priori knowledge of the Principle of the Uniformity of Nature.
5. Since Hume’s argument says nothing specific about inductive
reasoning, his conclusion can only depend on the fact that
inductive reasoning is not a form of deductive reasoning.
6. Premise 5 is false: inductive reasoning is a form of abduction
(inference to the best explanation), which is rationally justified.
7. The inference from premises 2 and 3 to 4 is invalid: we can
“observe” necessary causal relationships and, therefore, know of
their existence independently of deductive or inductive
reasoning.
8. The inference from premise 1 to 2 is invalid: neither of the two
basic forms of reasoning—deduction, induction—can be
defended in a non-question-begging way.
9. Premise 5 is false: inductive reasoning can be modified so that
the conclusions of inductive arguments say only that something
is probably true.
10. Accept the conclusion that inductive reasoning in science
cannot be rationally justified. However, it does not matter
because scientific reasoning is fundamentally deductive rather
than inductive. (Popper)