A scientist argues: 'Induction must be reliable because in the past, inductive reasoning has always led to correct predictions.' What is wrong with this argument?
AThe argument is valid — past success is the best evidence we have for any method's reliability
BThe argument is circular: it uses inductive reasoning (past success implies future reliability) to justify induction, which is exactly the inference whose validity is in question
CThe argument is valid only if applied to natural sciences, not social sciences
DThe argument fails because science has made wrong predictions in the past, so induction hasn't always succeeded
This is Hume's circularity problem. Any attempt to justify induction by appeal to its past success is itself an inductive argument — it assumes the future will resemble the past, which is precisely the assumption that needs justification. Option D gets the point wrong: induction's occasional failures aren't the core issue. The deeper problem is that even if induction had always worked, appealing to that track record still commits the very reasoning move under scrutiny.
Question 2 Multiple Choice
Which of the following best captures what Hume concluded from the problem of induction?
AWe should stop using inductive reasoning in science because it is logically unjustified
BOur practice of inductive inference is psychologically compelled by habit and custom, but we cannot provide a non-circular rational foundation for it
CInduction is valid only when sample sizes are sufficiently large
DThe problem of induction shows that probabilistic reasoning is the correct framework for scientific knowledge
Hume was not a skeptic about the practice of induction — he recognized we cannot help but reason inductively. His conclusion was that our inductive habits stem from custom and psychological compulsion, not rational justification. We cannot give a non-circular argument for why the future should resemble the past. Option C confuses sample size (an empirical concern) with the philosophical justification problem. Option D describes the Bayesian response to Hume, not Hume's own position.
Question 3 True / False
The problem of induction shows that inductive reasoning is unreliable and should be replaced with deductive reasoning in science.
TTrue
FFalse
Answer: False
Hume did not argue that induction is unreliable or that we should abandon it. He argued that it cannot be given a non-circular logical justification. We continue to rely on induction because we cannot help it — custom and habit compel us. Moreover, deductive reasoning alone cannot generate new empirical knowledge; it can only draw out what is already implicit in premises. Science requires both.
Question 4 True / False
Popper's falsificationism substantially solves the problem of induction by showing how science can proceed without inductive inference.
TTrue
FFalse
Answer: False
Popper's response sidesteps rather than solves the problem. By focusing on falsification (one contrary observation refutes a universal claim), Popper avoids needing to justify accumulating confirming instances. But this creates a new problem: Popper cannot explain why we should act on or believe unfalsified theories. If we have tested a bridge design 1,000 times without failure, Popper's logic doesn't tell us it's safe to use — he denies that confirming instances justify belief. Most philosophers consider this an inadequate response.
Question 5 Short Answer
Why can no finite number of confirming observations logically prove a universal scientific law, and why does any attempt to justify this inference seem to require assuming what we're trying to prove?
Think about your answer, then reveal below.
Model answer: A universal law covers infinitely many cases; observations cover only finitely many. The inference from 'all observed F are G' to 'all F are G' is not deductively valid — the premises don't guarantee the conclusion. The future could deviate from the past in any way logic permits. Any attempt to justify induction by saying 'it has worked before' uses inductive inference itself (past success predicts future success), making the argument circular. There is no non-circular path from particular observations to universal conclusions.
This is the heart of Hume's problem: induction is not deductively valid, and any non-deductive justification of induction must itself rely on inductive reasoning. The circularity is unavoidable within the framework of requiring rational justification. Responses (Popper, Bayesianism) either change what justification means or abandon the requirement for it — they do not derive justification within Hume's original framework.