Deductive reasoning: big to small (Everyone who surfs is cool, I surf, I am cool) - two premises of the inference (first two statements)
- conclusion (third statement)
- premise = a previous statement or proposition from which another is inferred or follows as a conclusion
- if the premises are true, the conclusion must be true too.
Inductive reasoning: small to big (I've never fallen while surfing, I never fall when I surf)
- premiss of this inference does not entail the conclusion: it is possible that I fall while surfing, despite that is hasn't happen yet.
- scientist use inductive reasoning whenever they move from limited data to a more general conclusion
- can we say a theory is proved, when inductive reasoning has been used?
- Popper: falsify a theory, so you can use deductive reasoning - this piece of metal doesn't conduct electricity (theory = now falsified), it's false that all pieces of metal conduct electricity. Is this a good manner?
David Hume: induction cannot be rationally be justified at all. We seem to presuppose that objects we haven't examined are similar to objects of the same sort that we have examined (Uniformity of Nature). Is Uniformity of Nature provable?
Peter Strawson: Induction is one of the standards we use to decide whether claims about the world are justified, so it makes little sense to ask whether induction itself is justified (example of law, law book, legal law?)
Inference to the best explanation (IBE): cheese is gone except for a few crumbs, scratching noises were heard - the cheese was eaten by a mouse.
Is ordinary induction ultimately dependent on IBE? Or is it the other way around?
One explanation for an occasion is always better than two (or more) - mouse declares the disappeared cheese as well as the scratching noises.
Subjective interpretation of probability: telling us how likely they think something is (probability is not objective)
Logical interpretation of probability: a statement's probability is the measure of the strength of evidence in its favour
Probability is used widely in daily life but also in scientific theories.