==Popper's Solution To the Problem of Induction==

• Induction is unjustified, hence irrational (<- Hume would agree) -> **We shouldn't use induction
  • We don't (need to) use it
• "Science is rational in deductive terms"

==Simple Inductivist Picture of Science==

• Facts acquired through observation -(induction)-> Laws -(deduction)-> Predictions or explanations ![[Pasted image 20231023193021.png]]

==Inductive-Hypothetico-Deductive Model==

• Facts acquired through observation -(induction)-> Hypothesis -(deduction)-> Predictions (for testing) -(passes tests)-> Laws -(deduction)-> Predictions or explanations

==Hypothetico-Deductive Confirmation==

• H -> P
  • Test P
  • If P is true, confirm H
  • If P is false, reject H
• Ex:
  • H = all metals expand when heated
  • P = this strip of copper expands when heated
• What does confirm mean?
  • proves?`
    • P1: If H, then P
    • P2: P
    • C: Therefore H => Affirming the consequent (deductively invalid) cf. Deductive validity: If the premises are true, the conclusion must be true => H-D confirmation cannot be deduction.
• Universal statement: ***All X are ~

==Hypothetico-Deductive Disconfirmation==

• If H, then P
  • Test P
  • if P is false, reject H
• Ex.
  • P1: If H then P
  • P2: not P
  • C: not H
    • Modus tollens => Deductively valid

==How Science Works==![[Pasted image 20231023193203.png]]

• Scientists are always choosing between hypotheses
• Ex: H1 v. H2
  • Prediction: H1 -> P1, H2 -> P2
  • Carry out experiments to test P1 and P2
    • P1 fails -> H1 is falsified
    • P2 succeeds -> H2 could either be T/F
  • Rational choice: H2
    • Scientists have preferences
    • We can never say that a hypothesis is true/probable,
      • but we can say that it didn't fail the test
    • We can never know whether a universal statement is true

Review Question:

• *How would you describe the philosophy of science?