Chalmers What is this thing called science - Alcestis PDF

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A. F Chalmers: What is this thing called science Introduction The book describes reasons for doubting that facts acquired by observation and experiments are as straightforward and secure as has traditionally been assumed. Scientific knowledge can neither be conclusively proved nor conclusively disproved by reference to the facts. The great embarrassment in scientific theory is that the major advances in science have not been achieved in a way that the philosophy of science say they should have been.

1 Science as knowledge derived from the facts of experience ● ● ● ● ● ●

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Is science derived from facts? We want it to be but we cannot prove that it is. The facts are presumed to be claims about the world that can be directly established by a careful, unprejudiced use of the senses 1700-1800. John Locke, George Berkeley and David Hume all proposed that knowledge could be derived from perception, from the facts of experience. Empiricism and positivism share the common view that scientific knowledge should in some way be derived from the facts arrived at by observation. Solely the object viewed but also on experiences, knowledge and expectations of the observer does not determine visual experiences. Before an observer can formulate an observation statement there must be a conceptual framework for what is observed. The parent points at something and says "Apple" and then the child knows some features of an apple. Before the child can classify something as being an apple it has probably seen a number of apples. There is a continuous interplay between facts and theory

2 Observation as practical intervention The scientist seldom observe facts directly as they are but creates circumstances that isolates only the details that the scientist wants to observe. This is how the complexity of the world is handled. ● The scientist may try to modify the world and then observe what happens. This is an example of even further intervention in the world ●

3 Experiment Its not just facts that are needed, but relevant facts. It may be necessary to manipulate variables. Some variables are held constant and some are manipulated and then it is easier to draw conclusions ● Scientific results come more from experiments than from observable facts. ● The acceptability of experimental results is theory driven. ● ●

The stock of available experimental results is constantly updated. Old results are rejected and new are proposed because of: 1) new measurements, 2)New knowledge and understanding of the problem ● The relationship between theory and experiment may involve a circular argument

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4 Induction ● ● ● ●

The number of observations forming the basis of generalisations must be large The observations must be repeated under a variety of conditions No accepted observation statement should conflict with the derived law Induction goes from facts to laws and theories, while deduction goes from laws and theories to predictions and explanations

5 Falsificationism ● ● ●

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There is a danger with self-affirmative systems like Marxism, psychoanalysis and many religions Even if a theory is not proven to be true one can claim that it is the best available theory If a theory should be useful it should be possible to explicitly state how it is possible to prove that the theory is false. If this cannot be proven in any way than the theory is not good. For example: A raven that was not black has been observed. This shows that the statement: "All ravens are black" must be false. Falsifiable statements are those when an observation statement can prove that the theory is false ○ It never rains on Wednesday ○ All substances expand when heated Non-falsifiable: ○ Either it is raining or it is not raining ○ Luck is possible in sporting speculation Whenever you make definite claims about something this is an indication that it is falsifiable The more precise it is formulated the more falsifiable it is The more general the claim the higher the status: ○ Mars moves in an ellipse around the sun ○ All planets move in ellipses around the sun Nobody can deny that falsification is good, but many can deny that it is useful. Bold conjectures are seldom falsifiable. If we only would admit theories that can be proven to be true or untrue into science we would omit most of all useful theories before they were even investigated. Science starts from problems since observations are only relevant in relation to some theory

6 The growth of science

A hypothesis should be more falsifiable than the one for which it is offered as a replacement ● Ad-Hoc modifications of theories are those with no testable consequences ● Both the inductivist and the falsificationist view of confirmation is needed ● Sophisticated falsificationism does not need credit from repetition as does induction

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7 Limitations of falsificationism ●

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Nothing in the logic of a situation requires that it is always the law or theory that should be rejected on the occasion of a clash with observation or with experiment. On the contrary. This would be highly dangerous since it could kill promising theories Conclusive falsifications of theories by observation is not achievable We did not abandon Newton just because some of his results were wrong. We can always deflect falsification to some other part of our large web of assumptions If we would have applied falsificationism on the work described in history we would never had achieved any scientific results Neither inductivist nor falsificationists give an account of science that is compatible with it.

8 Theories as structures. Kuhn's paradigms ● ● ●

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Statements and the concepts figuring in them will be as precise and informative as the theory in whose language they are formed is precise and informative. A concept emerges from a vague symbolic form in the unconscious to a gradual clarification as the theory in which it plays a role takes on a more coherent form. Development of science: ○ pre-science ○ normal science ○ crisis ○ revolution ○ new normal science ○ new crisis ○ etc.... The paradigm distinguishes science from non-science. According to Kuhn, Sociology lacks a paradigm All paradigms will contain some anomalies but this does not mean that the paradigm should be falsified. There will always be anomalies Periods of normal science provide the opportunity for scientists to develop the esoteric details of the science The weakness of Kuhn is that it is not possible to find out whether one paradigm is better than another. It depends on the values of the group or of society.

9 Theories as structures. Imre Lakatos ● ●

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Research should follow positive and negative heuristics Thomas Young's theories of wave won few supporters but the same theory as presented by Fresnel won many supporters. The difference was the positive heuristics that surrounded Fresnel. The researcher should be as a historian who identifies hard core issues and creates a protective belt around these Science is carried out as a competition between programs Lakatos make a distinction between appraisal of research programs which can only be done with a historical hindsight and advice to scientists Lakatos claimed that there is no instant rationality in science Theories should be tested against the history of science The weakness of Lakatos theories is that it is very difficult to identify the hard core of a science. Especially when it concerns new hypotheses. If a hard core is needed no progress will be made If Copernicus had followed Lakatos advice the whole research program should have been eliminated since Lakatos claims that all programs that do not have a hard-core should be eliminated. Lakatos based it all on physics and claimed that science must share the basic characteristic of physics

10 Feyerabend's anarchistic theory of science ●

History: ○ Science is special because it is derived from facts. This was false since facts are theory dependent ○ Falsification failed since science it not able to locate the cause of a faulty prediction ○ Kuhn and Lakatos tried to solve the problem by focusing on the theoretical framework in which the scientist work, but Kuhns theory failed since who knows which program is better than another?, and Lakatos failed because it was so lax that no intellectual pursuits could be ruled out ○ Feyerabend claimed that there exist nothing like a scientific method that is useful for scientists ○ The principle was "anything goes" ○ Feyerabend shoed that all progress in science has not been the results from following any type of scientific method. If the method cannot even make sense of Galileo's innovations the method is not applicable. ○ Some scientific programs cannot be compared since they are based on entirely different perspectives and thus the scientists cannot communicate with each other.

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Feyerabend criticized Kuhns proposal about consensus as a criteria since it did not rule out politicking or crime Feyerabend claimed that holding the scientific method as a morel is dangerous because this would inhibit more than it would help F. proposed a humanitarian attitude, the cultivation of individuality which alone can produce well-developed human beings The state must be free from science just like the state is free from church. Free society from the strangling hold of an ideologically petrifying science. F. can be criticised for not counting with the active role of society in creating individuals. Individuals are created into a society the pre-exists them

11 Methodological changes in method There are many indications to believe that a universal and ahistoric method is highly implausible and even absurd. It would lock science into a fixed position and make it dogmatic instead of adaptable. ● A universal method or no method at all does not exhaust all possibilities ● Galileo showed that we cannot rely only on the naked eye-observations since we use tools to observe ● Chalmers proposes that there is a universal method seen from a common-sense perspective since most scientists agree on a number of basic criteria ●

12 The bayesian approach Maybe probability calculus is the answer. Its not true or false. It is more or less probable. ● Abduction from many indications increases the probability using Bayes theorem. ● If a person is out in the rain without an umbrella he gets wet. He was out in the rain without an umbrella. => deduction ● If a person is wet this is an indication he was out in the rain without an umbrella => abduction ● The more indications the better P(h/e) = P(h) * P(e/h) .........................P(e) where P(h) = prior probability, e = evidence, P8H/e) = posterior probability after the evidence e is taken into the account ● The criticism against Bayesian approach is that the reasoning often is based on subjective interpretations and thus we do not get the hard core of classical experimental results as we do in physics. ● However, according to the "Bayesians" we can start with low probabilities and then successively get higher and higher probabilities until we have knowledge enough to perform experiments of a more classical type ●

13 The new experimentalism

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According to Robert Ackerman experiments can have a "life of their own" independent of large scale theory. Science could be based on practical strategies to retrieve more relevant information to proceed with experiments Science learns from mistakes. Experimentalists do this better than Popper because if research is based on falsificationable theories there is no explicit guidance to how we can use the data from failures. Experiments are not based on paradigms or theory but on previous experiments, and are independent of high level theory. Galileo did not have a theory about the moons of Jupiter. Experiments are guided by theory but not high-level theory. As soon as they are indicating something a switch is done that shows how the results relate to theories. The new experimentalists have not shown how high-level theory can be eliminated from science

14 Why should the world obey laws ● ● ● ● ●

Epistemological questions. How scientific knowledge is proven by the use of evidence Ontological questions. Questions about the kind of things that exists in the world Laws as regularities => they show patterns Laws as characterisations of powers and dispositions => We describe the world according to our own needs Thermodynamic and conservative laws. The energy is constant in a closed system. There is, however, no cause and effect. Only relationships.

15 Realism and anti-realism ● ● ● ●

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The enduring part of science is the one that is based on observations and experiments We find out about the world not only by observing it but by interacting with it We need a meta-language to be able to talk about a language Anti realists are often called instrumentalists. The anti-realists claim that there must be a distinction between the knowledge and the observational level. They advocate productive theories in favor of true theories. The critics claim that a productive theory is no proof at all that the theory is true. Scientific realism => We cannot know if our theories are true but we can know if they are "truer" than our old theories The conjectural realist knows that all our theories may be false. The very idea that we can declare past theories as false shows that we are heading in the right direction Unrepresentative realism and structural realism. The realist points out the success of predictions. The anti-realist shows that theories that previously made successful predictions are today considered as false....