Johanes Kepler’s (1571-1630) employment of observation and math enabled him to supplant the Pythagorean theories of perfect heavenly spheres by showing how planets moved in ellipses. Galileo Galilei (1564-1642) was placed under house arrest for agreeing with Copernicus.
So proceeded the process of investigation of the world, which has culminated in our discovery of the ultimate constituents of life and matter, and of the first moments of the existence of universe.
THE TRADITIONAL VIEW OF THE SCIENTIFIC METHOD
1. Observe nature: “Apples falling to the ground”.
2. Identify patterns and regularities: “Apples always seem to fall on my head”.
3. Formulate a hypothesis: ”All objects fall”.
4. Formulate a theory (generalisation about, say, hundreds of dropped objects): “Objects fall with constant acceleration”.
5. Use the hypothesis to make a prediction: “The marble and the brick I throw from different heights in different cities will fall with the same acceleration”.
6. Observe or experiment to test the prediction.
7. Limit the hypothesis if necessary: “Helium balloons need to be excluded from all objects”.
8. If the hypothesis has been tested extensively and seems to apply everywhere in the universe, a law of nature results: “F= mg, g=9,8 m/s2
Science uses inductive reasoning – generalisations based on evidence – as the basis of justification. A sound scientific conclusion will be based on a large number of examples, on representative samples, and on observations made repeatedly.
Inductive reasoning can never give certainty, because:
1. Except in very rear cases, we cannot observe every single example within defined group;
2. We cannot be sure that the generalisations we have made based on the past will continue to hold in the future, e.g. Vancouver Island has not had a major destructive earthquake. Can we therefore conclude that it will not have one in the future (daily warnings are received, that one is immanent).
This inductive conception was discredited by Karl Popper (Logik der Forschung, or The Logic of Scientific Discovery, 1935). He presents a view of scientific discovery, which does not use induction at all.
Scientific reasoning according to Popper:
1. Scientists do not work forward inductively, step by step. Instead, they conjecture inductively and creatively ahead of the facts, to frame hypotheses.
2. These hypotheses are then tested deductively. That is, the hypothesis is taken for the moment as truth. What consequences would then follow if it were true? This way of thinking, reasoning form the general supposed-truth (the hypotheses) to specific examples to which the generalisation would then apply, is deductive reasoning, and guides the researcher to various possible experiments to test the hypotheses. This approach is called the hypothetico-deductive method.
3. Statements in science can never be verified because of the uncertainty inherent in induction. They can only be falsified, or refuted by evidence. Scientists accept only those statements that have been tested and not yet falsified.
4. The difference between science and non-science – the “criterion of demarcation”- is that scientific statements are open to being falsified. They must be able to be tested.
It must be possible for an empirical scientific system to be refuted by experience.
Thus the statement “It will rain or not rain here tomorrow” will not be regarded as empirical simply because it cannot be refuted, whereas the statement “It will rain here tomorrow” will be regarded as empirical.
Thomas Kuhn
Like Popper, T.Kuhn agrees that all observation is theory laden. Scientists have a worldview or paradigm. The paradigm of Newton’s mechanical universe is very different to the paradigm of Einstein’s relativistic universe; each paradigm is an interpretation of the world, rather than an objective explanation.
According the T.Kuhn’s analysis in The Structure of Scientific Revolution (1962), we can discern 5 stages in the model of scientific progress:
- Pre-paradigm stage
During this stage there are likely to be many rival schools, each with a different view of the phenomenon being studied. Some people might think the earth a disk, with balls of fire circling round it; others might think it a sphere, circled by things made of some different substance; yet others might think there holes in the sky, revealing a fire beyond (people have believed all these theories).
- The establishment of a paradigm
Eventually, one of the pre-paradigm schools (or perhaps some totally new theory) will become notably more successful than any of its rivals: it will succeed in explaining far more, or in making extremely successful predictions, and will attract adherents.
- Normal science
The scientific community sets about answering the questions, which are posed by the paradigm. In this stage the scientist does not do his research randomly, but holds a theory first and than makes observations. Only those results of observations are accepted, that fit into a framework of a paradigm. It means, that research is not done objectively, and theory directs our eyes in particular direction, when others might also be possible.
Before the 17th century, the universe was seen as geocentric, according to the Ptolemaic model. This image of the galaxy was produced not by observation but by reflection and reasoning. In 380 B.C. Aristotle proposed that the Earth was the natural centre of the universe and in II c. B.C. Ptolemy described the system in detail. Of course, human beings were the centre of God’s creation. A Ptolemaic model, a legacy of nearly 2000 years, was also very deeply entrenched in the thinking of the Christian Catholic church.
- Crisis
In his stage an accepted theory fails increasingly to explain anomalous findings – odd bits of information that do not seem to fit into pattern, bits of data that are not very useful, because we cannot incorporate them into explanation that we already understand.
Referring to Ptolemaic example, during the 16th century, astronomers failed to fit new findings into the Ptolemaic model.
- Scientific revolution
- A whole new way of explanation – demanding that the old data be interpreted in a new way, which incorporates the anomalous findings – replaces the familiar theory. Kuhn calls this abrupt shift from old theory to new theory a paradigm shift. Scientific community often meets it with extreme resistance.
In 1543 Copernicus, the polish priest, using the same data as Ptolemy did, concluded that the Sun, not the Earth, was in the centre of the universe. His hypotheses went largely ignored, though his observations and calculations influenced many astronomers. Galileo (1564-1642) was persuaded early in his career of the truth of Copernicus heliocentric model of the Universe, but hesitated to put forward his ideas. After the invention of telescope (1609), Galileo built his own, and used it to make observations that were not possible before that time. In 1611 he demonstrated the use of telescope to Church leaders in Rome, and, encouraged by their interest, expressed his support to the ideas of Copernicus.
Hi ideas were met with extreme version of the resistance of which Kuhn speaks. Finally after publishing in 1632 his Dialogue on the Two Chief World Systems, Ptolemaic and Copernican, he was forced to recant and sentenced to house arrest for the remaining eight years of his life.
According to Kuhn, paradigms are incommensurable, i.e., the new theory cannot be built using the same terms as old. In the case of Copernican revolution, heliocentric universe cannot coexist with geocentric.
Kuhn favours pragmatic approach over any notion of correspondence: “I do not doubt, for example, that Newton’s mechanics improves on Aristotle’s and that Einstein’s improves on Newton’s as instruments for puzzle-solving. But I can see in their succession no coherent direction of ontological development” (p.205-206).
Many scientists have echoed this. Erasmus Darwin, brother of Charles, said, “If the facts won’t fit in, why so much worse for the facts”. Paul Dirac, Nobel Prize winning physicist, said, “It is more important to have beauty in one’s equations than to have them fit the experiment”.
Paul Feyerabend
Feyerabend convincingly argues that methodologies of science have failed to provide rules adequate for given the complexity of history:
“Case studies/…/ speaks against the universal validity of any rule. All methodologies have their limitations and the only “rule” that survives is “anything goes”.
Given the complexity of any realistic situation within science and the unpredictability of the future as far as the development of science is concerned, it is unreasonable to hope for a methodology that dictates that, given some situation, a rational scientist must adopt theory A and reject theory B.
“Anything goes” should not be interpreted in too wide sense. The scope of the applicability of this “Anything goes can be exemplified by the difference between reasonable scientist and the crank:
“The crank usually is content with defending the point of view in its original, undeveloped, metaphysical form, and he is not at all prepared to test its usefulness in all those cases which seem to favour the opponent, or even to admit, that there exists a problem. It is this further investigation, the details of it, the knowledge of difficulties, of the general state of knowledge, the recognition of objections that distinguishes “respectable” thinker from the crank”.
In his view science is a religion, for it rests on certain dogmas that cannot be rationally justified. Thus accepting it requires a leap of faith. But just as government has no business teaching religion in the public schools, it has no business teaching science either. In a truly democratic society people would be as free to choose their epistemology as their political party: “… the separation of state and church must be complemented by the separation of state and science, that most recent, most aggressive, and most dogmatic religious institution” (“Against method”, 295).
Feyerabend complains that defenders of science typically judge it to be superior to other forms of knowledge without adequately investigating those other forms. He observes that “critical rationalists” have examined science in great detail but their “attitude towards Marxism or astrology, or other traditional heresies is very different. Here the most superficial examination and most shoddy arguments are deemed sufficient”. It cannot even be assumed, without further investigation, that a form of knowledge under investigation must conform to the rules of logic, as they are usually understood by contemporary philosophers and rationalists.
SCIENCE AND PSEUDO-SCIENCE
Any theory, which is in principle impossible to falsify, is not a scientific one. So if we explain certain events, say, by poltergeists, we may predict that these poltergeists behave in a certain way. If they then fail to behave in this way we should reject the theory as falsified or change the theory. So far this is good science. However, if we change it t o retain the poltergeists, but say, “they only appear when they want to”, than this is pseudo-science, because now we cannot find any data which could falsify the theory. This is common indication of pseudo-science – any data will fit into theory.
Against Method: Outline of an Anarchistic Theory of Knowledge, London: New Left books, 1975, p.295-296.
“Realism and instrumentalism: Comments on the logic of Factual Support”, in The Critical Approach to Science and Philosophy, ed. M.Bunge. New York: Free Press, 1964, p.305
