Study Questions for Lectures 11 (Bayesianism and Evidence)
Instructions: Please answer all of the following questions while, or after, you watch the lecture (or read through the notes).
- What is hypothetico-deductivism? How is it supposed to free us from Hume’s problem of induction?
- Explain one of Glymore’s two problems for hypothetico-deductivism.
- Explain the motivation behind Goodman’s comment that hypothetico-deductivism allows for “indoor orthinology.”
- Describe the difference between prior probabilities and conditional probabilities.
- Explain how the two notions described in Q4 can be used to give a simple and elegant theory of scientific evidence.
- What is the difference between objectivism and subjectivism with respect to probabilities?
- According to the subjectivist, who is the ideally rational person (note: there’s no need to list any axioms here) and how do you determine the prior probabilities for this (ideally) rational person?
- According to the objectivist, how might one determine the prior probability of some claim, h.
- Which do you think provides a better view of probabilities: subjectivism or objectivism? Argue for your answer.
Hypothetico-Deductivism
•The idea goes back to logical positivists
•Hypothetico-Deductivism: the idea that a hypothesis is confirmed (or corroborated?) when its logical consequences turn out to be true.
•“All swans are white,” implies that the next swan one sees is going to be white.
•If we suppose that the next swan you see IS indeed white, then that is taken to be evidence that ALL swans are white.
•For the hypothetico-deductivist, to give evidence for a hypothesis doesn’t require an argument; it simply requires that the consequences of a hypothesis indeed turn out to be true.
•This, in fact, is a routine method of reasoning in science; we even teach it to freshmen students enrolled in “critical thinking” classes!!
•But there are SERIOUS (and simple!) problems with this way of thinking.
