Unit 1. What can we know? [Philosophy of Science]

1. Unit 1 What can we know?

2. What is science?

3. Write down what you think science is Name five examples

4. The traditional view of science Science comes from the Latin word scientia which means knowledge. Science gives us knowledge of reality. This knowledge is objective, generalisable, controllable

5. Philosophy comes from the Greek φιλοσοφία (philosophia) which means love of wisdom. Philosophy studies general and fundamental problems. The philosophy of science can help us reflect on the nature of science.

7. The definition of science effects real life

8. Rationalism and Empiricism

10. Deductive reasoning goes from all (a general rule) to one (a specific case). Inductive reasoning goes from one (a bunch of single data) to all (a general conclusion). A priori= before experience A posteriori = after experience

11. Rationalism and deduction

12. Descartes (1596-1650): Doubt your senses

13. What if there is no God, but just an evil demon tricking us Then I might be sleeping, dreaming I am awake

14. But the demon can never trick me into the idea I don’t exist. Cogito ergo sum?

18. Deduction Deduction is logical reasoning. Deductive knowledge is a priori knowledge that is known independent of experience. Deductive arguments are purely logical.

19. a deductive inference Standard example of a deductive inference: Premises All men are mortal. Socrates is a man. Conclusion Socrates is mortal.

20. Empiricism and induction

21. Induction Inductive knowledge is knowledge based on sensory experience. Inductive knowledge is a posteriori knowledge, knowledge that is gained by experience (that is, it is empirical, or arrived at afterward).

22. David Hume’s (1711-1776) fork

23. Analytic: statements about ideas Synthetic: statements about the world

24. Example of an analytical sentence: All bachelors are unmarried. Example of a synthetic sentence: All bachelors are bald.

25. Hume’s problem was that it is almost impossible to go from synthetic to analytic statements.

26. Because we can never relate the analytic sentences to the real world it is meaningless, they only speaks about them self. Consider the example of the bachelor: it is a tautological sentence, it is always valid regardless of your data.

27. A thousand white swans Take the example of a white swan. Can we be certain that if we see a thousand white swans, that all swans are white? No. Even if we have a thousand observations like: this swan is white, we can never relate this to the rule all swans are white. Only if we would see every swan in the universe – now and in the future- which is impossible.

28. The fact that the sun has risen everyday up until now may not prove that it will rise tomorrow, but surely it gives us a very good reason to think it will?