1. Philosophical Aspects of Science Soraj Hongladarom Department of Philosophy Faculty of Arts

2. Outline What is science? What is scientific methodology? Logical structure of scientific knowledge How does science differ from other forms of knowledge? Explanation of the success of science

3. What is Science? Standard definition: ‘systematic investigation of the natural world through empirical methods and theoretical framework.’ Problems with the definition How can many different disciplines be brought together under the same heading? Physics and biology Is psychology a science? Is history a science? Why or why not? What is meant by ‘systematic’?

4. Origin of Modern Science Aristotle Argued that heavier things fell faster than lighter things - why? Also argued that woman did not contribute any genetic material to the embryo - woman only provided the matter, while the male provided the form. Aristotle’s method - he collected a lot of samples, but did not experimentation.

6. Astronomical Systems Ancient systems Some Greek astronomers argued that the earth revolved around the sun, so it was not Copernicus who first brought about the idea, but the idea did not catch on. Ptolemy perfected the system where the earth is at the center, but he encountered a lot of problems trying to reconcile the system with the actually observed data.

9. Reactions against Aristotle Aristotle was the authority of the Church. Reaction against Aristotle was equal to reaction against the Church. Nonetheless, Galileo tried to prove Aristotle wrong. This shows the characteristic of modern science - reliance on the means of knowing that everybody already has: reasoning and observation. Aristotle used that too, but he went too far on reasoning.

10. Copernicus As is well known, Copernicus suggested that the earth revolved around the sun rather than the other way round. However, he did not observe that the earth moves around the sun. He simply put forth his ideas as a hypothesis. But his system was much simpler than Ptolemy’s and as a result was accepted by astronomers. The reason why it faced a lot of resistance was that it ran against the beliefs at that time that the earth does not move.

11. Modern Science We can pause and look at what modern science is about. Logical structure of science Hypothesis Deductions from the hypothesis Comparison with actual observed data Experimentation Confirmation or rejection of the hypothesis The hypothesis becomes a theory when it can explain a large number of phenomena.

12. Theory and Law A scientific theory is a set of statements serving to explain a number of phenomena in a systematic and coherent manner. Deductions from the theory can be used to test it through actual observation. Examples: Newton’s Gravitational Theory; Einstein’s Relativity Theory; Darwin’s Evolution Theory

13. Theory and Law A scientific law, on the other hand, does not serve to explain phenomena, but succinctly states how certain phenomena behave. Examples: Newton’s three laws of motion; Boyle’s law on pressure; Einstein’s famous law -- e = mc 2 Problem - why are there laws in physics and chemistry, but not in biology?

14. Scientific Methodology Many believe that what makes a science a science is something called ‘scientific methodology’. This is believed to be shared by all the ‘scientific’ disciplines, such as biology or physics, chemistry.

15. Identification Form hypothesis Test hypothesis Does the result confirm the hypothesis? No – do further testing or reject hypothesis Yes – the hypothesis is confirm. A system that explains hypothesis is called theory.

16. Problems with the Standard Picture What determines the identification of the problem? The picture seems to lead us to think that scientists are free to identify any problems that they are interested in. But in fact there are a lot of other factors influencing their choices, most of which depend on socio-cultural or economic reasons.

17. Problems with the Standard Picture Underdetermination of theories Sometimes the same set of data can support one or more theories Hence it is hard to say which theory is the true one

19. How does science differs from other forms of knowledge? This is known as the ‘demarcation’ problem If we have a standard scientific methodology, the picture is simple: Whatever follows the methodology is science; whatever does not is not. But it appears that different sciences follow the methodology quite differently. Biology and astronomy consist mostly of observation and classification; whereas chemistry and physics involves a lot of experimentation.

20. Role of theories Biology does not rely as much on theories and laws as do physics and chemistry. Some believe that all scientific disciplines can be reduced to physics, which is regarded as the most basic. But can we use physical theories to explain biological phenomena? The point is that even within science there are differences.

21. Karl Popper The philosopher who advocated the demarcation problem is Karl Popper. His idea is known as ‘hypothetico- deductivism’ -- all scientific knowledge proceeds through setting up hypotheses and deduce the consequences. When the test result does not conflict the hypothesis, it is accepted as knowledge, but when it’s not it is rejected.

22. How does astronomy differ from astrology? Both used to be the same, until astronomy became ‘scientific’ in the 17th century and distanced itself from astrology. But where exactly are the differences? According to Popper, astronomy follows HD, while astrology does not. But astrology can follow HD too!

23. HD in astrology Hypothesis: Those born under the influence of Venus are pretty and love sex. Deductive consequence: Sutheera is born in May, which falls under Venus. Therefore, she should be pretty and love sex. Through observation, Sutheera is really pretty and she does love sex a lot. Therefore the hypothesis is confirmed and astrology is indeed scientific.

24. HD in astrology Hypothesis: Those who are born under the influence of Jupiter tends to be happy and optimistic. Deductive consequence: Pornthep is born in December, which falls under Jupiter. Therefore, he should be happy and optimistic. However, observation shows that he is anything but happy and optimistic. Therefore, the hypothesis is contradicted. But this does not mean that astrology is not scientific, because there may be other influences that can explain why this happens.

25. The demarcation problem Popper’s demarcation attempt thus faces a lot of problems. The idea of HD does not seem to work well. We are still searching for the real demarcation that separates science and non-science. Perhaps the difficulty lies in the fact that we are still unsure what in fact is science from the beginning.

26. Explanation of the success of science Another way to demarcate science from other forms of knowledge is that science seems to be successful. So success may be the determining factor. But then there seems to be a change in the rules. Earlier the rule seems to be that science gets at the truth, whereas other forms don’t. But Popper’s problems prompts those who want to defend the demarcation to turn to success. Problem is: Success is not the same as truth.

27. Success and truth There are many indications that success and truth need not be the same -- a statement can be successful without being true. But if that is the case, then to argue for demarcation by relying on success is changing the rule.It is as if one admits that science does not always lead to truth.