The philosophy of science course makes me think about the science itself dialectically, what science is, how to understand it and what the attitudes we should keep are to realize it.
The characteristics for genuine science come up with some philosophers are seen as demarcation criterion. The Karl Popper’s theory shows that the important difference between science and pseudoscience is based on the refutability or testability or falsifiability. It is unlike empirical work which is mainly gained form observation and experiment. The astrology is considered to be pseudoscience by Popper because it is not testable and refutable. But in Thomas S. Kuhn’s theory, he thought that the understanding of science should not only be the basement of objectivity, but also the attention to the subjectivity. His criterion for Astrology which he thought was not a science was that it was not to solve puzzles. It was more like practical arts . The scientific research is to make hypothesis which should be on the basis of facts and previous theories, and try to make exception to falsify the hypothesis. And then make new hypothesis or abandon it. This is a procedure like trial and error.
According to Lakatos’s theory, the demarcation of science and pseudoscience has an important relationship with political and social issues. It’s hard to tell the demarcation and it’s more like the difference to distinguish the methods in researching scientific and non-scientific theories. Some theories, such as “all creatures die out”, are testable and refutable. If one of all the creatures is found to be never dead, the theory turns out to be wrong. But it is impossible to find the result because we can not predict the future. Such kind of theory we put forward is just based on a logic thought. Lakatos was to explore which research program was more proper instead of seeking whether an assumption was genuine.
The science is relative to social values which generates the objectivity of science. In Longino’s theory, the observation and statistics are often used as the evidence for the assumptions, but they are determined by human opinions. These called evidences are divided to support the different kinds of assumptions. And only those reasonable assumptions with supported evidence may be accepted by people and be viewed to be true. In Kuhm’s opinion, science progress via revolutions. This is also viewed as paradigm change. That is to say, science comes form the stages: prescience, normal science and puzzle-solving.
In the positivism, Carnap made a relationship between scientific and phenomenalistic terms using logical syntax. He also combined explanation with laws which can be used to predict new things and explain the existing things . But to Hempel, when talking about idealized and everyday reasoning, he thought the explanations didn’t have to be made to every detailed thing. And phenomenon or facts can be added to those explanations which make them more persuadable.
In Lyotard’s theory, the ontology is switched to the validity of knowledge and the status of intellectuals to show his digestion of identity and integrity and Metadiscourse exile .
 Boman, Magnus. Philosophy of Science, course notes, KTH, 2010.